|Volvo 240 Mods & Fixes
Just a few cool mods to keep you sane and properly entertained.
|UPDATED: November 5, 2018 CONTACT|
|D O M A
I N S
|N A V I G A T E T H I S P A G E|
|Guide for CRIMPING TERMINALS
||Electric Cooling Fan Info|
|4-Speed Fan Controller||AutoCoolGuy PWM Fan Controller||Painting 240 Taillamps
|Stepper Idle Valve Project
||240 Interior Refresh
||Gentex Mirror Upgrade|
|Yoshifab Turbo Oil Drain Tube||Yoshifab Catch Can Install||Oil Cooler Information|
|Oil Cooler Thermostat||240 Door Top Black Vinyl Trim||Electric Power Assist Steering|
|240 Steering Rack Identification||Classic Car Insurance||Classic Auto Air AC Installation|
|Mechman High Amp Alternator||Cracked 240 Dashes||Rear Wheel Spacers|
|Wider Rear Wheel Clearance||Calculating Wheel Offset||Momo Steering Wheel Hub Fix|
|240 Headlight Switch Plug||240 V Belt Sizes||240 Headlight Switch Plug|
|Super Bright Dome Light|
|240 Hydraulic Clutch Info||240 Driving Light Brackets||Lowering Your 240|
|240 Cup Holder Project||G80 Diff in your 240||Fixing Underhood Grounds|
|Benefits of Anti-Corrosive Paste||HARDWIRE Your 240 Taillights||Quick Taillight Repair (FOIL)
|Later Windshield in your 240||Headlight Relay Harness||The 240 Headlight Step Relay|
|Step Relay ELIMINATION||Speedo Recalibration||Bulb Failure Sensor PART 1|
|Bulb Failure Sensor PART 2||Bulb Failure Sensor PART 3||Faster Better WIPERS|
|Mods using RELAYS||Komfort Blinker Upgrade||M46 OD Harness|
|Auto Trans OD Harness||M46 / M47 Shifter Knob Fix||In-Tank Pump Upgrade|
|Fuel Pump Relay Mod||240 Tach Install||Plastic Fuel Line Repair|
|240 (52 mm) Small Tach Install||Bad 240 Door Lock Wires||Temp Compensation Board|
like 240s a lot and there's nothing
I like better than modifying them for performance, handling, comfort,
In this page I have outlined some cool mods I have done to my 240s and others that have been provided by other 240 enthusiasts.
Your comments are welcome: CONTACT
|Guide for Crimping
I've put together a page with instructions for crimping and assembling typical open barrel or EFI crimp terminals and connector housings.
Experiments in the Installation of a
Primary Electric Cooling Fan for your 240
When in good working order, the original belt-driven clutch fan in your 240 can handle most cooling needs. But if you have been thinking that your 240 needs an electric primary cooling fan, here is a page I put together on my experiences with a number of electric fan conversions over the years, from small 14 inch GM fans to big Ford or Lincoln fans. Plus a variety of wiring diagrams are included for building your own relay fan control systems if you like.
Cooling Fan Controller Project
(for my LINCOLN MARK VIII fan)
In 2016 I got tired of failing high-tech fan controllers that would burn up after a year or two when trying to control my big Lincoln Mark VIII fan. They always failed in the worst places. So I decided to design and build my own fan controller with FOUR speeds using what I know. RELIABLE RELAYS. Works great! You can build one too if you like.
Click here: http://www.240turbo.com/fanharness.html
PWM Fan Controller Installation
(for my LINCOLN MARK VIII fan)
New addition in 2018.
Click here: http://www.240turbo.com/ElectricCoolingFans.html#autocoolguy
Painting 240 Taillamps
I get questions about the taillights on my car occasionally. These lights originally began as ALL CLEAR lights like in the below photo. At the time, finding half-clear lights was not possible. They can be found on eBay now. I didn't want all-clear lights, so I painted the bottom lenses myself using the below Testers transparent red paint, 1605 Gloss Custom Red. This paint is easy to use and goes on pretty well. It takes several light coats to get to the shade of red I got. Let it dry between coats and keep adding paint lightly until you have the red you like. It will slowly darken with each coat. These lights have been on my car for well over 10 years and still look new. Part of this reason is the car is always garaged.
If you need to tint in AMBER, I have not tried any transparent amber paints yet, but I have heard of good results from the below Tamiya TS-73 Clear Orange for Plastics.
I have also read that you can get good results from a transparent STAINED GLASS paint. Kyrylon makes such paint in aerosol in ORANGE and RED. I have not used these yet.
Stepper Idle Air Control Project
In 2018 I began working on a stand-alone manually adjustable idle control valve for my car using a GM stepper IAC motor.
Click the above images or below link to see it.
240 Interior Renewal Project
This discussion thread began in May 2018 and it's a goldmine for inspiration on making your old 240 interior look new again. It's a great resource for information on paints and interior parts too, so I had to share it here for those of you who haven't seen it.
Gentex Rear View Mirror UpgradeAdding a more modern mirror for your 240 on the CHEAP.
with Auto Dimming, Compass and Outside Temperature.
Drain Hose for Volvo Turbo Red Blocks
Yoshifab Catch Can (breather box) Installation
This information may come in handy when working on oil cooler systems on red blocks. The oil flow direction was import to me when I decided to install an in-line oil cooler thermostat between the engine and oil cooler. My factory 240 oil thermostat seemed to be no longer working and stuck in the wide open position. The new in-line thermostat required specific flow direction for "in" and "out" ports.
If you can help add to this information, please email.
The factory oil cooler thermostat in my 240 Turbo oil filter plate seemed to have stopped working. My guess is it was stuck in the wide open position, since it was taking forever for the engine oil to come up to temperature. So I decided to add an IN-LINE oil cooler thermostat in the lines between the engine and the oil cooler.
If you can help add to this information, please email.
Removing or Replacing 240 Door Top Black Vinyl TrimI gets lots of questions about doing this kind of work or where someone can buy these black vinyl trim pieces.
They have not been available for a lot of years from Volvo or any other source, but if you're persistent, good results are possible.
If you want new black vinyl for your 240, contact me. I can supply the new stripes you'll need.
CLICK HERE: http://www.240turbo.com/doorvinyl.html
Electric Power Assist Steering
If you like having power steering, but for some reason the traditional hydraulic setup isn't quite right for your modified Volvo (or if you want to convert an older manual steering Volvo to power assist) here are some possible answers.
A number of years ago, Josh Sadler of Yoshifab converted his Volvo 242 to electric/hydraulic steering. Josh's system was failrly simple. It used the original Volvo power steering rack. He mounted an electric/hydraulic steering pump and reservoir from a Toyota MR2 in his trunk and had hydraulic hoses made to route all the way to the stock steering rack. The result worked pretty well.
Here's a discussion thread on his installation: http://turbobricks.com/forums/showthread.php?t=135556
See his YouTube video below.
Here's another more detailed thread on a different MR2 pump installation in a Volvo: https://forums.tbforums.com/showthread.php?t=247548
And here's the next generation mod.
It's an electric power assist unit from a Saturn Vue, Chevrolet Equinox or Pontiac Torrent. It's mounted in the steering column, so the level of tech is much higher.
This was an installation under the dash of a Volvo P1800 (pics below).
See the discussion thread here: http://forums.turbobricks.com/showthread.php?t=341174
Here's a supplier of just such kits that you may be interested in seeing: http://www.epowersteering.com/index.html
Identifying a Power Steering Rack in your 240
Classic Car Insurance for your Classic VolvoThis is a bit of an unusual subject for a mods page, but I know it will be helpful to some Volvo owners out there.
Classic Auto Air all new Air Conditioning InstallationI finally grew tired enough of my mediocre Volvo AC in my 242 to explore an extreme option. This is a complete new AC system installation from Classic Auto Air. I also spent the time installing Dynamat while the interior was out of the car. It was a LOT of work, but sometimes hard work really pays off.
I created a new web page all about the new AC conversion. CLICK HERE!
I did this installation a number of years ago in my 242.
I began a discussion thread in Turbobricks back then, which helped me get through some issues I was having. That thread is here: http://forums.turbobricks.com/showthread.php?t=215613.
Dealing with a Cracked 240 Dash
Other threads to read:
There are some good reasons why you might want wheel spacers or wheel adapters for your 240.
When my 242 had these Eiker wheels (photos here: www.240turbo.com) I was annoyed by the large gap between the rear tires and the outer fenders.
Wheel/Tire FENDER CLEARANCE
for your 240
When going with wider tires on your 240, you'll need to deal with the likely result of rear tire rubbing on bumps, especially if your car is lower than stock. The back half rear arch may need to be trimmed by 1/2 inch or more, depending on your ride height and how far the tires need to tuck inside the fender when compressed. Some people prefer to ROLL the inner sheet metal instead of trimming. On many cars this is a pretty easy thing to do, but not on a 240. The 240 sheet metal at that place is TWO LAYERS, which makes rolling very hard. Most people who use the rolling method on a 240 end up finishing with a sledge hammer because rolling alone didn't work.
The area marked in RED is the general area that needs rolling to reduce tire rubbing on medium bumps. This is the FIRST (but not only) rubbing area you will encounter when your tires get pretty CLOSE to the fenders.
Here's a good thread with pics that outlines the ROLLING/HAMMERING METHOD pretty well: http://forums.turbobricks.com/showthread.php?t=338190
In my opinion the above rolling/hammering modification does not go far enough if your car is lowered and you want to TUCK the rear tires without hitting metal or if you want to retain full suspension travel all the way to bump stops. Rolling the outer lip reduces rubbing at the back arch only.
<<< If you need your wider tires to go HIGHER in the fenders like this photo, you will need to do much more.
The below illustration will help explain what I did on my 242 when I went with the BMW mesh style wheels and adapters with 235/40-17 tires that are pushed out fairly close to the fenders. My trimming of the outer lip started out slowly, a little at a time in a trial and error method. Then I cut and removed the inner sheet metal curvature that prevents the wheel from tucking all the way up. This resulted in perfect clearance and the car could FULLY BOTTOM OUT the rear suspension in a hard dip with ZERO rubbing. That means hitting the bump stops with no rubbing. That's never gonna happen with rolling alone.
The below illustrations show how this was done.
I have been told this is similar to the modification made to Group A race Volvos to fit their large wheels/tires.
When I was shopping for wheels to replace the Eikers, I knew I would need to concentrate on something with more offset than the Eikers, since I would need the extra room to add an adapter behind each wheel. I eventually settled on wheels that were 7.5 inches wide with 35 mm POSITIVE offset.
The adapter maker I chose was http://www.motorsport-tech.com.
When I contacted them, they said the minimum thickness they could do was 20 mm. So I went with a 20 mm thick front adapter.
There it is. That's how it's done. Draw yourself some diagrams if it helps you visualize all this.
Here's a good Turbobricks discussion thread with related info: https://forums.tbforums.com/showthread.php?t=339645
Turbobricks Wheel Guide: http://forums.turbobricks.com/showthread.php?t=72501&highlight=wheel+guide
Rim and Tire Size Calculator for Custom Offset calculations: https://www.wheel-size.com/calc/
Wheel Hub for the 240
Installing a Momo (or similar type) steering wheel in your 240 can really improve your driving experience. It gives you lots of options for choosing a stylish or sporty steering wheel in a variety of sizes.
You probably already know all this and luckily for you, that's NOT what this article is about.
|240 V Belt
Information on 240 accessory V belt sizes used to be easier to find, but it seems to have mostly dissappeared from many useful sites.
I put this info together many, many years ago for my own 240 uses. I thought I would share it here.
If you can add to or help with this info, please email.
Headlight Switch Plug Problems
So here's the formula needed to swap in a newer headlight switch and plug.
1. White wire from old plug goes to position 1 in new plug.
2. Yellow wire from old plug goes to position 5 in new plug.
3. Red wire from old plug goes to position 4 in new plug.
More information on adding a RELAY to upgrade your early 240 headlights can be found here:
MORE VOLVO BULB REFERENCES
Matthews Volvo Site Bulb Guide: https://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=61483
Other 240 interior and exterior bulb info in this Turbobricks thread: http://forums.turbobricks.com/showthread.php?t=283706
iPd Bulb Reference: https://www.ipdusa.com/techtips/10096/what-light-bulbs-fit-my-volvo
Volvo has owner's manuals going back many years (bulb info is in "Specifications"): https://www.volvocars.com/us/own/owner-info/owners-manuals
Clutch Info Page for your 240
I have a pretty heavy clutch in my 240. Back in 2011 I got tired of stretching, adjusting, stretching and then snapping clutch cables, so I installed a hydraulic setup for the clutch. I recently updated the master cylinder from the Volvo unit to an aftermarket one and created a web page to help keep track of the parts and information for others to see.
Here's the new page below:
Driving Lights on your 240 without Drilling your Bumper!
a Custom Cup Holder for your 240
We all know our beloved 240s never came with cup holders. There have been a number of cup holder projects in the internet over the years. When I saw this one in the Turbobricks forum, I felt it really needed to be shown. The thoughtful design allows it to be securely anchored over the e-brake handle, using the e-brake handle button to help pin the front against the shifter hump. It's a nice design feature to keep in mind when you build (or adapt) such a thing for your car.
See more photos and dimensions here: http://forums.turbobricks.com/showthread.php?t=328054
|Installing a G80 Locking
a 700/900) into your 240
Also, here's the link to my old 240 Limited Slip Rear End Page. Some info is out of date, but I leave it up for those who can use the info.
|Fixing Common Corroded
(and power connections)
In Your 240
I hear about strange intermittent electrical problems from frustrated 240 owners quite often. These problems occur so often because of a few good reasons . . . .
|Hardwiring your 240 Taillights (Tail Lamps)
|Quick Fix to get your 240 Taillight Bulbs
to Work Again (using aluminum foil).
If you have the above circuit board issues and don't have the time or patience to hard wire your bulbs (above), here's a quick fix. Thank you to Michael Yount for offering this solution.
Simply cut some small pieces of aluminum foil and place them on your circuit boards as shown in the photos. Use some hobby tacky glue to keep them in place. They will help bridge the bulb holder circuit if you have worn out circuit boards.
Lowering Your 240
Should you change the ride height of your 240? That's a question that comes along often enough. You have to decide if you like your car at the original ride height (cause you drive in floods?) or if it looks better to you a little lower. Sometimes the road conditions in your area will help you decide, since lowering a car means a more firm ride and less undercar clearance. If you decide you want to lower it, here are some options to consider.
Sport Springs: Most sport springs that are available (iPd Sport Lowering Springs being the most popular brand) will lower your 240 about 1.5 to 2 inches. Other spring companies offering 240 springs: B & G Suspension, King Springs (Australia), Classicswede.co.uk (UK).
The ride will be a little stiffer, but it will be very important to use good struts and shocks that will be able to control a stiffer spring. Bilstein HD shocks or Koni adjustable shocks are a pretty good match to this type of spring.
Adjustable Coil Suspension (Coil-overs): These are nice if you can find them. They offer a wider range of adjustability allowing the use of a variety of coil stiffness and adjustable ride heights. Occasionally there are people who produce kits in small quantities for 240s. Usually not though. If you're handy, you can build your own set.
Here are some good resources:
240 Coilovers: The Kyote Way
DIY 240 Series Coilover Instructions
Search the Turbobricks forum for more.
Cutting your Stock 240 Springs:
There are people online who will scream at you to never try this! I think it's because there are more failures from inexperience than great successes. The key to getting it right is experience and getting it right is definitely possible.
And for more you can read the following threads, particularly the posts from Tuff240 (author of the above page), who has more experience cutting 240 springs than anyone I know. This is the best information possible on this subject:
a Badass HEADLIGHT HARNESS
This is a good project for anyone with any older Volvo, especially if you have or want to to upgrade to brighter bulbs or headlights.
For the best info I know, read Daniel Stern's page on this subject. He also has several useful diagrams for designing and building your own relay harness.
Here are some Volvo specific diagrams that have been available on-line for many years. These use the same principles:
UPDATE 2018: Wagonmeister is now offering ready made 240 headlight relay harnesses.
|Unlocking the Mysteries of
Headlight Step Relay
And Test Procedure.
This relays is rather special in that it has a LATCHING function. A latching function is where you can click and release a momentary button or switch (such as a high/low beam stalk) and the relay will LATCH (or lock) in the ON or OFF position until the switch or stalk is clicked again. For this Volvo relay, one click latches it "ON" and another click latches it "OFF." I have created the diagram PDF at the left for anyone who wants to better understand how these relays work. I have also added a test procedure on page 2 if you think you might have a broken one.
to Substitute Available Relays
to ELIMINATE your Volvo 240 Headlight Step Relay
Resources for more info: https://www.brickboard.com/RWD/volvo/853622, http://forums.turbobricks.com/showthread.php?t=239021, http://forums.turbobricks.com/showthread.php?t=258248
Understanding and Dealing with a Volvo Bulb Failure Sensor
Part 1 of 3
a Volvo Bulb Failure Sensor
Part 3 of 3
Making some simple BYPASS LEADS for a Quick and Easy Fix.
If you don't feel like modifying a Bulb Failure Sensor, there is a simpler way to bypass these circuits without using one. And I don't mean to suggest cutting off the multi-pin plug and splicing wires together (which of course you can do if you like). A better method, with no barbaric butchery, is to assemble some simple crimp terminals with a few short pieces of wire. Then insert them into the multi-pin connector, respective of the bypass diagrams shown above As it turns out, the multi-pin connectors for these sensors use fairly common 3.5 mm bullet terminals. So all you need are some male bullets and wire. Coincidentally, these 3.5 mm male terminals and insulators are available cheap in my Harness Parts Page HERE.
In the photo at left, you can see how these will look. The configuration is different for some sensors, so pay attention to the diagrams above.
Volvo using Relays
I'm putting this here because having an understanding of simple relay functions can help any DIY Volvo mechanic in so many places for your car projects. Many of the suggestions in this 240 modification page rely on relays. Not too many years ago my relay knowledge was limited to installing a pair of fogs lights. The internet has helped a lot in this area and most of you can now be really successful with relays.
This Relay Guide is not Volvo specific, but it's a great resource for expanding your general auto relay knowlege and offers some interesting diagrams.
http://www.davebarton.com/pdf/RelayGuide.pdf (3.3mb PDF)
Here are some other pages with more relay explanations and configurations:
http://www.danielsternlighting.com/tech/relays/relays.html <<< And this is the best site I know for improving your auto lighting with added relays.
If you know of any other useful resources that would be a good fit here, please email me.
(Blinker) 3-FLASH UPGRADE for your Volvo
using a VW/Audi Komfort Blinker Relay
240 M46 Overdrive Wire Harness Design, Construction, Mods
240 Auto Transmission Overdrive Wire Harness Design and ConstructionSince I did the above M46 diagrams I thought it would be good to illustrate how the 240 auto trans ORANGE and WHITE overdrive relays work. There is almost no difference in the relay circuits between these two relays. They are essentially interchangeable, EXCEPT that the OD light on the dash seems to come on opposite of when it's supposed to when the other relay is installed.
In-Tank Fuel Pump in your 240 with a Larger 740 Turbo Pump
The Bosch in-tank fuel pump found in your 240 Turbo will be the same pump used in all 240/260 models from 1976 to 1984. It's very small and while it will provide adequate fuel for a non-turbo Volvo, it has been considered by many to be too small for a turbo motor with any increased engine performance. The Volvo part number for the original in-tank pump up to 1984 is 1276330. In 1985, that part number changed to 3507436, which was used through 1993. The 740 Turbo pump I used for this conversion, which was used from 1986 and later in 700 and 900 Turbo models, as well as 960 models, is PN 3517845. This pump retails for between $150 and $200 new. It is also widely available in salvage yards for a lot less, although you should be cautious, because some pumps found in salvage yards may be dead already. For my 240 Turbo, I chose to install a used pump from a salvaged Volvo. If you need to test a pump with a battery, do it very briefly... only a second. These pumps are not designed to run dry and it can damage them quickly.USEFUL LINKS ON THIS SUBJECT
|Add a Secondary
to take the High Load off your 240 Fuel Pump Relay
The fuel pump relay in your 240 takes a lot of abuse and it's expected to run your fuel pumps for years and years without fail. Well fail they do, usually because of unwanted heat after years of use.
They often run hot because; 1. They handle a heavy load. 2. The heat causes their plug connections to develop higher resistance, which then causes more heat, which makes a failure occur like shown in this photo.
Below I have outlined how I added a standard 4-pin relay (or 5-pin will work too) to handle the pump loads, giving the original pump relay a much welcomed rest. The new added relay can be any standard 4 or 5 pin type relay with a load rating of 15 amps or higher, such as the ones I offer in my relay page here: http://www.240turbo.com/volvorelays.html#1324749-006brown
What this does is take the heavy load off of the expensive Volvo relay and puts it on the inexpensive standard relay. Then the Volvo relay is only used as a low current switch to activate the standard relay.
The new standard relay is triggered by pin 87 on the original fuel pump relay and receives its main battery power from pin 30 of the original relay circuit. As an option, you may instead run a dedicated battery wire to pin 30 on the new relay. I suggest 12 gauge wire. This should provide a bit more voltage to your pumps. If you do this, then the wire should always contain a fuse between the battery and relay.
Below diagram is for K-Jetronic Volvo 240.
CLICK TO ENLARGE PHOTO
Below diagram is for LH-Jetronic Volvo 240.
CLICK TO ENLARGE PHOTO
your Volvo 240 in place of the Large Clock
Adding a tach to my '83 240 DL way back in 1990 was the first 240 mod I ever did to a 240. It's a very basic install, but can be a bit puzzling for a beginner. These instructions will also show you how the small clock is installed.
CLICK HERE FOR INSTRUCTIONS (pdf)
Volvo used semi-rigid plastic fuel lines on all 200, 700 and 900 series. Probably a lot more models, but I'll deal mainly with cars made in the 1980s and 1990s for this article.
Special thanks goes to Roger Brown of Pueblo, Colorado for the photos and details from his own fuel line repair. The photos below are of 740 fuel lines, but the principle is the same for 240s.
You'll find that the plastic hoses used in these cars are fitted to fairly standard brass or steel barbed nipples. Volvo fitted them when the hose or nipple or both are heated to a point the plastic becomes more flexible. Removing these hoses from existing nipples can be difficult and you may find that cutting or slitting them at the barb is the best treatment.
Here's a video of the general idea.
While less popular than adding a large tachometer to your gauge cluster, Volvo made a small 52 mm tachometer available for 240 owners.
They are fairly rare these days, but they can still be found used. Here are diagrams for wiring it up.
CLICK HERE FOR INSTRUCTIONS (PDF - Right Click and Save)
Bad 240 Driver
Door Lock Switch Wires
I have seen a fair number of emails like this one:
"I own a 1993 Volvo 240 Sedan. It has about 100,000 on it and runs beautifully. The only problem is that the central locking system seems to be malfunctioning. It makes a fast clicking sound when driving and sometimes goes up and down when one tries to unlock the other doors from the drivers side. In the past two days the battery died due to something being left on. I pulled the #8 fuse (courtesy lights, clock, trunk light, glove box light, central lock system, power antenna, radio) and today the battery was fine."
This is an extremely common problem that literally affects ALL YEAR 240s equipped with CENTRAL DOOR LOCKING.
How do I know this problem is common in all year 240s? Because when I discovered this years ago i spent time at junkyards pulling off door panels on a lot of 240s up to the 1993 model year. They are all the same. All had BAD WIRES!
The problem is old, flaking wire insulation inside the driver door. Specifically, the wires going to the key lock switch ("F" in the diagram shown at left) and also the door lock plunger switch ("A" in the diagram shown at left). It should be pretty obvious once you pull off your door panel and look closely at these wires. The insulation on these wires will crumble and fall off, allowing the wires to short. This causes the rapid lock-unlock to occur randomly. And when the car is parked, the shorted wires may allow the locks be stuck in UP or DOWN mode, which can drain your battery in a few hours. The solution is to cover the bad wires with heat-shrink tubing, liquid electrical tape, etc., or cut them out and crimp or solder in new wires. You will probably only have to do this to about 8 inches of wires, but keep an eye out for more than that.
Here are a couple good threads with more photos: http://forums.turbobricks.com/showthread.php?t=323301, http://forums.turbobricks.com/showthread.php?t=322700
Dealing with the Temperature Compensation Board in your 1986-93 240
I won't go into great detail here, since there is already an excellent article on this subject linked below. In a nutshell, Volvo got tired of people complaining about fluctuating needles on coolant temperature gauges. Fluxuating coolant temperatures is normal, however when the gauge fluxuates, many customers get freaked out by it. The coolant thermostat is supposed to even things out. But Volvos in the 1980s were designed for cooler northern European climates and there are many U.S. regions that will easily max out an old 240 cooling system.
To make customers happy, for the 1986 year model Volvo began installing a special circuit board in the instrument cluster that changed the function of the coolant temperature gauge so that it would remain stable in the middle or "normal" range at all times unless the engine was very cold or very hot. The gauge then had only a few set readings instead of a true variable reading. Customers were happier.
These temperature compensation boards generally worked fine until they got old and began failing. A failing board would cause mysterious high or low fluctuations for no reason. If you're trying to determine what your high or low temperature fluctuations REALLY mean, you can buy an infrared (IR) temperature reader and check your top radiator hose temps for abnormal changes. If you find that temperatures are actually pretty stable, then your temperature compensation board may be failing.
To fix the problem, iPd began offering a simple bypass wire you could buy for cheap: http://www.ipdusa.com/products/5670/108262-temperature-board-bypass-kit. They also offered replacement compensation boards for more money.
You can also read the following instructions for your own DIY repair . . .ARTICLE HERE: http://cleanflametrap.com/tempFaker.html
And if your interested in more DIY repair, Peter A. submitted the following:
"The circuit is kind of clever. It can be repaired rather than just eliminating it. It does require a soldering iron and a solder sucker to desolder the old parts.
Pretty much the only things that will fail is the integrated circuit U1 or output transistor Q1, both of which can be purchased on-line from Digikey or similar places for about a dollar. U1 was bad on my board. After 25 plus years it would also be wise to replace the electrolytic capacitor C1."
Click here for a PDF diagram and photo of these circuits: http://www.davebarton.com/pdf/TempBoardCircuits.pdf (270kb)
And Dirk W. submitted the following for those interested:
"Lots of people will claim you need a new temperature compensation board (PCB), but that's not what's really wrong most of the time. I have found that the metal pins that are mounted to the main cluster PCB are generally not properly soldered to the PCB. They APPEAR to be soldered, but if you touch a soldering iron to the solder blobs that cover the heads of the pins, you will find that the solder is not wetted to the pin heads and these connections are almost always bad somewhere. A little work with some sandpaper on the heads of the pins and resoldering the heads of the pins to the PCB will fix most temperature gauge issues."
|New Items||Cool Volvo Products||Volvo Stickers||Steering Wheel Labels||Prancing Moose Stickers|
||Other Car Stickers
||Classic Auto Air AC||4 Speed Fan Controller||Limited Slip Read Ends||240
Mods and Fixes