Can anyone tell me how the engine temperature gauge (stock) in an 89 Camaro is wired. Does the gauge share it's temp sensor with the computer, or does it have it's own sensor? Anyone ever had a gauge itself go bad?

My problem is that the gauge does not appear to move above the 140 degree mark. I didn't think anything of this, as it is still cold and I have a 160 degree thermostat (don't drive in winter), but when running the car the other day, the primary fan came on. I have an aftermarket chip, but it's not suppose to come on at 140.

 

i would sugested hooking up a an obd1 scanner and seeing what your actual coolent temp really is and campare it to the guage . that way your will no if its right or not. .. jsut a thought.

 

The dash Temp gauge uses a "sending unit". The ECM has its own "coolant temp" sensor. You can test the dash gauge by unplugging the sending unit wire, this should cause the gauge to read "max temp". If NOT you have a bad gauge or partially shorted wire. If it does max out, then the sender is bad.

 

I don't know where the sender is on an 89. On my car it is on the driver side of block, under the first or second spark plug. It is a one wire connector that slides sideways onto the top of sender.

 

Thanks for the info. I'll have to find the temp sensor and give that a try. If everything check out, might have to look into the computer, maybe the ECM temp sensor is bad. Any idea where that one is?

 

The ECM/sensor has nothing to do with the dash gauge. If your fan is working, the ECM/sensor is working.

 

Thanks. I was thinking if the gauge & sensor were OK, the ECM temp sensor might be wrong, causing the computer to turn the fan on too early. Seems less likely, but just a thought.

I'll start with the gauge temp sensor, see what happens. Thanks for the help.

 

The gauge will read 'full hot' when the sender wire is grounded. The gauge, unless it or the ignition switch is broken, will do a full sweep while cranking the engine to start it. This tests the gauge (by grounding it via the ignition switch) to show it's working and has full range of motion.
v8, any year, will have the sender in the driver side head. A single green wire is connected to it.

 

OK well the guage only moves about 1/3 of the way up when starting the car. If I remember correctly, it's actually about the same position that it would top out at. Does that suggest it's the gauge? Can I just swap the gauge itself for another, or should I be looking elsewhere for a problem as well?