OEM coolant temp gauge - which wires?

from the 3 screws in the back… what is each wire?

i want to try to apply direct power/ground/signal to the gauge…

somewhere in my car, it’s not making a correct connection, or something is messed up… but i replaced the gauge, and it isnt working, but the sending unit works fine because using it to send a signal to a aftermarket temp gauge, it gives a reading… but with the stock setup, it doesnt…

Yellow is 12V+, [fuse 23 in under dash fuse box] yellow/green is from sending unit and black is ground.
My Haynes manual doesn’t show what term. the wires go to, you will have to trace that from the plug/s to the terminals, you can use a test light or multimeter and test the term. while the cluster is still plugged in, one term. will be switched 12V+, [if you can’t find one with 12V+ on it, and the fuel gauge and tach. work the problem is between the cluster plug/s and the gauge] another term. will be the ground, [constant], [same thing as the power, if fuel gauge and tach. work, the problem is between the plug and the term].

The term. that is left over is from the sending unit, to test the gauge, [with it still plugged in] use a jumper between ground and sending unit term., [ign. must be on], if gauge goes to the top it’s good and if you have 12V+ and ground at the gauge then, [as you suspect] there is a break in the yellow/green someplace between the terminal and the sending unit,

Hope this helps :hmm: 94

i finally got down to tearing it down, and found on another thread the pinouts of the harness to the gauge cluster, and as you said it was yellow/green . and after i found out which wire it was, i checked for continuity, and there wasnt any… so i ran a new wire from the sensor, cut & spliced into the wire that goes into the harness…

now it works! thanks fcm, your DA man…

really though, thank you for all your help, you’ve helped me out over a dozen or more countless times with misc. wiring problems with my car… :bow:

Yw :slight_smile: 94