The temp gauge tac in my 87 iroc 305 TPI, is all the way down. Where would I start to fix it? I changed the CTS yesterday and its still doesnt work. The guy I bought the car from said he fixed it once but it only worked when he started the car and shut the car down and when he started the car back up it hasnt worked since. I need this gauge to work bc I am trying to fix the probelm I am having with the fan. All the other gauges work, sometimes the oil tach jumps up and down but I hear thats normal

 

The sender for the temp gauge is in the head on the driver's side between the #1 and #3 spark plugs. Should have a green wire going to it . See if that is as it should be
The CTS tells the computer what the temp is

 

Thanks! I was in there changing the spark plugs on this side last week and must have knocked mine loose. Found it with your help and the gauge in the dash is working again.

 

My temp gauge works. I took apart the dash, started the car it moved. Turns out the needle was stuck behind the bezel. The resistors are bad.

 

Oh well I guess you don't need my input...

 

i have a 90 irocz 305 TPI.. and the temp gauge is not working replaced and connected the sensors on both sides of the engine but still nothing... the fans work and turn on but the gauge stays at the bottom ...

Any ideas??

 

Remove the wire from temp sensor in the head and touch it to the block.
Watch what gauge does.
If nothing your temp gauge is faulty or the wire from the temp sender unit to the gauge is damaged

 

Sorry I know reviving old dead post is not liked very much but I knocked off the green wire on the passenger side and now my temp on the cluster is not working. The wire was hanging on by a thread. I know it was a ground wire. Any way I can get a easy fix? My fan I turn on manually. I just need to read my engine temp.

 

Any other tips or tricks to try for this problem? My needle just wiggles a little when car is on/running. Tried a new sensor on the engine side, same result. Gauge maxes out when I ground the wire, as I have been told it should if the gauge is okay...