I may be able to offer some advice on this one.
I bought my truck used and it had the temp/compass guage but it didn't work. I figured since it was the one part of the truck that didn't work that I could live with it, but sure enough I got curious and took it apart a few days later to see if I could find out what was going on.
When I tore it apart I found that the resistors on the top left of the board are contact not pin style and when laid on the board there is nothing holding it in except that solder. What I found was that the solder could not hold up to the high temps involved. If you take it apart and look you can see the solder is a "flat crackly faded silver" not a smooth finish like it should be. This solder had overheated and let my resistor fall a little so that one side was not connected anymore. After re-soldering it works like it should from the factory. If you look at the picture on the top page the resistor has a "510" labeled on the top in white and a black background.
This is what I would check first, but it may have just been mine and not a common theme.
Hope this helps, cause it's an easy fix with some nicer solder.
Also, mine is a 2005 so they may have modified the solder mix in the circuit board since then.
I don't want to jinx myself but after 50k mine has been okay so far.Yesterday we bought a 2006 Tacoma with a broken display. Dealer flatly refused to fix it. Now I know why.
Anyway, it took me twice as long to read through this thread than it did to fix the problem--which took less than 30 minutes.
It sure helps to have some soldering experience, and also a good soldering iron designed for use on small electronic components. A good flux-filled solder also helps. At one time in my career, I was an R & D technician, and did tons of soldering. Many thousands of little connections--came in handy--some things you don't forget.
The display works fine now. My fingers are crossed though.
That's what happens when you grind 'em down far enough on the price that they start squeeling like the pigs they are--if you know what I mean.....I don't think I'd be too happy if my dealer refused to fix it when I just bought the truck. For him it s a few minutes and a replacement module.
Thanks a lot,
For others to see I took pictures...
First I took out the screw behind the sunglass case, and then pulled down on the front of the overhead console by the temp gauge until these little metal clips popped off.
Then I pulled the console down, disconnected the wires, and removed the temp gauge. Sure enough, the solder had broken off and the resister was loose...
I re-soldered it... it's not pretty but it works. This was the first time I ever really soldered anything.
Put it all back together
and put it back in