Hello TGO,
I've been working on this problem for ages. I'm trying to diagnose where is the break (if any) between the temp. gauge sender/switch and the temp. gauge in the dash. When I turn on the ignition the gauge will go down to cold and will not move when you crank it or when it gets hot while running.

EDIT: I've done some searching, and I found ppl talking about if the sender/switch is bad, but not a lot of people talk about how to find the problem or break between the gauge and the sender/switch.

I've already put in a new switch/sender (the one on the drivers side behind the AC compressor, and I have already taken out the dash and tested the gauge with a 1.5 V battery and it pegged to hot all the way.

I'm trying to find out where the green wire runs but its hard to see. Seems like it goes toward the intake then down under the engine heads toward the passenger side goes around the smog pump and around the exhaust then back up back to the driver side in the back of the engine then gets connected to the firewall back at the drivers side and then goes to the dash on the other side I would assume.

There seems to be a bunch of wires that gets connected to the firewall, and it is near a bunch of relays on the drivers side. I wonder if that is a connector that I can take off to test the continuity with a multimeter?

 

Third time I posted this so it must be a useful link to wiring diagrams...
HTH!
https://www.thirdgen.org/forums/elec...-diagrams.html