How do you troubleshoot a broken coolant guage?
The needle on my coolant guage doesn't move at all when started, it stays below Cold always.
I know it haves to be something with the coolant temp sender, is it possible there's anything else that could cause it not to work?
The coolant and fuel is in one guage and the fuel one works fine, so i don't think it would be the guage itself.
thanks, i would just like to know where i can start to troubleshoot or maybe if there's loose connections somewhere i need to check
1991 toyota tercel
Answers & Comments
Verified answer
An open sensor or wire would cause the problem you describe. To check the gauge itself, remove the wire from the temp sensor and hold it against a metal surface on the engine. With the wire grounded and the ignition key to "on" the gauge should go to the "hot" peg. If it does then replace the sensor unit. If the gauge continues to read cold with the wire grounded then either the gauge is bad or the wire is bad. The gas and temp gauges may be in one unit but the gauges are still two different units. Just because one is good doesn't mean the other one has to be.
it depends on how the gauge is wired... some have the gauge on the hot side, others have the guage between the sender and ground..
use a jumper wire to check the guage from that open wire, to battery negative, and then from that open wire to battery positive, with the key on.
if the fuses are good, then the gauge should swing from one end of scale to the other, when you touch the positive terminal.
if not you have a break in the wiring or a faulty gauge.
If the gauge does swing, then the sender is bad...
breaifly unhook it and touch the wire to ground, any metal part on the engine..if the gauge or light comes on or moves then its the sending unit at fault.