ok I have a 86 se 2.8 with temp gauge that goes to 120 degrees.Replaced sender no change.Ground one wire the bulb comes on,ground the other wire gauge pegs 260.Fan cycles on and off.any ideas.
The fan works on a different sender. When you test to ground are you using the sensor housing or the engine block? Did you use any tape when you installed the new sender? The threads must be bare and clean.
Yeah the fan switch is up front but just saying it is cycling in relation to the gauge only reading 120 . I did not use Teflon but did use rtv on the threads.I didn't think that was the problem since it does come up to 120 and quit.
You probably are experiencing a problem that occurs on all Fiero's. The wiring to the temp gauge is wired in such a way that when you turn the car on it tests the idiot lights. When it does that it pegs the temp gauge and it eventually spins the dial out of calibration. I believe there are some on here who can point you to what you have to do to fix the problem. I had this problem and when I had my engine swapped one of the mechanics fixed my temp gauge.
So I would do a search of the forum for this problem or maybe visit the Ogre's Cave where he might explain it better and have the fix too.
At 100F your sensor for the gauge should have a resistance of 1400 ohms, and at 260 it should be 55 ohms (or lower). It appears that your sensor has failed.
Well after replacing alt,cts I think I found out why the gauge doesn't get over 130.I pulled the thermostat and the po had a 160 degree in there.So I need to figure out where to go.The 195 or the 180?
[This message has been edited by rcm (edited 10-21-2013).]
I put in a 195 thermostat and now the temp gauge is coming up to 175.Because the fan is coming on early and suspect the fan switch must be 160 to 180.Now I need to replace that one with a 210-200.