Hi,
1983 LG4 4 barrel trans am. The coolant gauge isnt working. Never budges from 100. The heater works great, doesnt overheat so I am guessing the thermostat is fine. I see (2) units. One on the thermostat housing and one on the end of the hose going into the water pump with wires. which one is the coolant sending unit? How can I test it to see if it is bad?

Thanks...I have a haynes book but it shows the v6 engine and doesnt really talk about the v8. Really want the guage to work in case I start overheating.

 

One wire sensor on driver's side cylinder head controls the dash temp guage. Look for a singe wire with spade type connector. It probably just came loose.

 

as naf said, it is on the driver side head. between the 1 and 3 spark plugs. mine likes to fall off also.

 

Hey Everyone,
No wire or sensor in the location you stated. My buddy has an 85 camaro (he has a special 82-87 firebird.camaro book) and it states that the sensor which controls the gauge is ontop of the thermostat housing (has a femail end on the top of the connector). Can anyone confirm truly if this is the sensor?

I know some sensor is bad because everything cooling wise works (i.e. good heat, not overheating, etc.) just the gauge sticks at 100. I disconnected the sensor wire and my check engine light went on so I know the wiring is good.

Thanks

 

the sensor in the t stat housing is for the computer, the sensor in the cylinder head is for the gauge.

 

Afraid the book's wrong. There are up to three temp sensors on your engine depending on year/model. The sensor in the water neck provides temp reading only to the ecm. The driver's side sensor connects only to the guage. Most models (except some pre-86) have a temp sensor/switch in the pass side head for the radiator fan.

 

Naf is the man, my sensor hasn't worked since I bought my car a year and a half ago. I always wondered what that thing sticking out the head was. Now I know what it is, put my hound down there, found a lose wire and it hooks right up, gauge works now. Thanks guys.