in the late 1980's 240s that have the temperature compensation board, how do you repace it? does it require soldering? I looked at mine and it doesn't seem to pull out, or am i wrong? This is the cause of my temp gauge not responding, right?

clueless in iowa,
Craig

I don't usually mess with them. At $35 apiece, they're pretty easy to replace. Take the cluster out. Mark the wires if you aren't familiar with them.

Then undo the back of the cluster from the front case. A bunch of little phillips screws undo it. The board is right underneath the temp gauge and slides into a socket, and is held in by two little tabs that you can release easily.

If you want to try a fix, solder terminal 1 to terminal 3 (with a jumper) on the board. I have had some success with that in the past. Usually, though, a new board does the trick better than anything.

Then button it back up. The yellow/red wire goes to the very lower left. The yellow wire goes to the double terminal near the speedo head. The rest of it is pretty self-explanatory. But CHECK before you undo them to make sure that's how they come off of there.

PS, if you have a tach, you'll have to deal with white/red wire as well.
--
1992 940 wagon, low miles
as well as others.

Tach wiring is not much more complicated:
white/red wire to the tach body itself
3-wire harness (red, black, green?) has a plug that
connects right into the back of the tach, and can only go
1 way. Powers the small clock that's part of the tach kit.
If the car has a large clock, just disregard this.
--
Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE: 625K total

If you send me your email I will send you an image that visually explains the steps to removing the compensation board and soldering in a jumper wire between two pins and you will not have to worry about it again. I have done it on three different cars and it works fine.

Randy

rstarkie, my email is bigsmellyass@hotmail.com
Thanks for the image!

Craig

Thank you everyone for your help!

Check out my post above. I (not so cleverly) didn't say WHICH was terminal #1 and terminal #3, because...

I have a "Cheater" dead compensation board in my tool chest that I've fixed up so that I can look at it every time I do one of these. My brain doesn't remember things like that. I soldered the jumper on it so I just copy it on a good working board. Is that pathetic or what? Like a three dimensional green manual for the temp compensating board.
--
1992 940 wagon, low miles
as well as others.

I have never soldered a jumper on the board and then reinstalled it. I just remove the board and solder a jumper between pins 1 and 3. The boards are still laying on my bench- along with a lot of other stuff that shouldn't be taking up space.

Randy

That's how I'm going to do it next time. I just read about the 1-3 jumper on the board in some trade mag so I did it that way. Next time, however, bye-bye board.
--
1992 940 wagon, low miles
as well as others.

Craig,

To inspect the temp board, it requires you to remove the instrument cluster from your dash. Remove the headlight knob, dimmer knob, and then pop off that plastic cover. You'll see two screws there. Where the accessory gauges go to the right of the cluster, pop off the gauge bezels (or gauge covers). You'll see two more screws. Remove them. I pull off the steering wheel horn cover to give myself more room to work with (for models with an airbag). Push both turn signal and windshield wiper levers down. Unplug all the necessary cables going into the cluster, and write down where each one plugged into to. After doing this, you should be able to pull the cluster out.

Once that's pulled out, remove the 7 screws that are on the outside edges of the cluster. After these are removed, you should be able to remove the cluster from its plastic housing. Look below the temp & fuel gauges and push that sucker back in and fully seat it. Or, if you want, pull the board out and inspect it.

Unless you did the above, I don't think that there's a way that you could have inspected the temp board to determine it was pulled out... ??

My temperature compensation board was loose (not fully seated in the socket). The gauge would sometimes register and sometimes not. Even when I traveled 400 miles to go upto Atlanta, the gauge not once hit 9 o'clock. In fact, it registered below that a majority of the way. I pulled the cluster one day, and found that to be my problem. Don Foster had posted several messages in the past with pictures on what circuits get fried, etc. on the board... Perhaps do a search on that if you are interested.

Usual symptoms of a bad temp board are spikes in the red zone. When it gets to that point, that's when you have to either replace the board or solder it.

Also check the yellow sensor wire that plugs into Cylinder #2 (?). Make sure that that's not loose.

Good luck...
Eric Staufer,
'89 244DL 117k

eek.. typo, I meant "I pull off the steering wheel horn cover" on models WITHOUT an airbag. Oops..

Regards,
Eric