I have two separate electrical issues I hope someone can help me with. I haven't got a Bentley manual and I can't make heads or tails of the wiring diagrams in the Haynes manual I have. Car is an 86 240 GL with ~250K mi.

First problem: My temperature indicator is not working. I have replaced the whole instrument cluster with another unit from a salvage yard. Prior to that, I attempted to clean the contacts of the compensator board. Occasionally the indicator would go to hot then settle back to dead bottom of the scale. I have also replaced the sending unit with one from a salvage yard. I am beginning to believe the wire from the engine is the problem. If I route a new wire in from the sending unit, which wire is the temperature indicator wire in the cluster? Please tell me the pin number and color of the wire.

Question two: Instrument lights are not working and I can't seem to trace a short that is popping fuses. I have 12v to the rheostat but if I connect the two(4) wires on the rehostat directly and bypass it, intermittently it blows a fuse. I would like to bypass this problem also and run new wire to power up my instrument lights only when the headlights are on. Suggestions as to how is best to approach this? Please specify wire colors to tap into on headlight switch, and pin number in cluster plug of instrument lights if possible.

Thanks a bunch

Bill