Ok, bought an 87 auto sr5 gage to put into my 86 delux. Everything looks close, but I had to move two wires for the fuel gage over one pin.

On the blue (A) connector I had to move every wire over except one for the temp gage over one pin to get the tach to work. This matched up with the 87 wire harness that I cut out.

Now everything works except the temp gage. It goes past 1/4 almost to 1/2 and stays there. I unplug the blue connector and it stays there. It will go there with only the C connector plugged in. the actual pin for the temp gage (by following the circuit board) is on the blue connector. But the temp gage goes up with the blue connector disconnected.

Anyone have anythoughts on this? I can't find any info on this particular situation. Thanks for the help.

 

time to go through the FSM wiring diagram

 

Anybody got any ideas on this one - seem to be having the same issue - was thinking it could be the sender but after some testing the sender is fine - it works with the old gauge fine, works with a thermostatic analog AM gauge fine too....... ????!!???