I have a 91 RS and I'm having a problem with my temp. gauge. The temp. gauge starts working like normal and then slowly goes to full hot within about 5 minutes even though I know my engine is not over heating. I've replaced my sending unit and still no change. Then I bought another instrument cluster and swapped out the center section that has the temp. gauge. It still didn't fix the problem. Then I tried putting all my original gauges into the instrument cluster that I bought, again no luck. Of course then I tried putting the center portion from the instrument cluster that I bought back into the instrument cluster that I bought, put it in the car and you guest it! It still didn't solve the problem. So after doing all the swapping out and using two different instrument clusters, all I can think of is that both circuit boards on each instrument cluster's are probably messed up. If any one has idea of what I can try next to fix this problem I would surely appreciate it.

Thanks

 

Are you sure you replaced the proper sensor? There's one in each head, one is a sensor for the temp gauge and one is a switch that grounds at a certain temp for the fans, they get mixed up a lot and I HIGHLY doubt the pcb is shot on 2 clusters....

 

I replaced the sensor located on the driver's side head. I'll try replacing the sensor on the other head to see if that makes any difference, even though I know my fan motor is still working. If you have any other ideas please let me know.

Thanks

 

Check the wiring, I had this issue with mine and juust bought a mechanical eqqus gauge from oriely, runs a capilary tube instead of a sensor, I just can't imagine that 2 pcb's are fried

 

I'll make sure to check the wiring. Is that the right spelling, (eqqus gauge)? I'm going to get on oriely's website and see if I can find one. By the way where is this gauge located at?

Thanks

 

 

remove the old wire from the gauge and sensor and run a new wire between them ( just a test wire is enough ) ( but make ***** the old wire aint connected to any of them.
( you can also put 12V on the right contacts of that extra gauge you got and then also run your new temperature betwen the sensor and the gauge. ( just for testing purposes.

if your problem is gone, you know there is something wrong with your wiring.
I had to run a new oil sensor wire because the old 1 is shorting out somewhere making my PSI go to 0 on my dash.

 

yeah two u's not q's, you take the sensor out of the head and then replace it with the capilary tube, it comes with a set of adapters, i cant remember which one it is exactly, id size it up to the old sensor if youve still got it, just get everything routed into the dash, thru the firewall, then get it ready by the sensor, i used teflon tape on it just to be safe, and then pull the old one and shove the tube in fast, thread and youre done its just the leaking coolant thats a PITA