Recently got my combo back together and noticed while idling the temp gauge was reading much hotter than the actual coolant temp (measured at the t-stat housing w/a DVOM).

I checked the ohm's resistance on the sender and for the given coolant temp it measured right in spec per the service manual. Just wondering if anyone else with the later style cluster has seen (specifically the temp gauge) inaccuracies like this...


Thanks​

 

I'm beginning to wonder if it's an issue with the printed circuit board the 3 smaller gauges rely on... Guess I'll be pulling the cluster out one of these days soon and see...

Any suggestions/comments are more than welcome 😎

 

The sensor for the dash temperature gauge is in the drivers side cylinder head. Between 1 & 3. It is a single wire sensor, dark green wire.

The two-wire sensor by the thermostat housing is for the ECM.

RBob.

 

Yeah, I see that in the oe wiring but this car had been simplified and all the efi wiring eliminated. The gauge worked for the years & years using the ecm sending unit (sensor) it's just all of a sudden as of late once the temp starts rising the needle continues to sweep (past the point of accuracy)