The 29 has an electric temperature gauge. Voltage goes to the gauge and the other wire goes to the sender and is grounded there. The two wiring diagrams I have both show the voltage coming from a post on the light switch that is always hot. Shouldn't it use a source controlled by the ignition switch so the battery isn't drained?
Not being familiar with the 29 electric temp guage (my 38 has a capillary tube type) but I would think you are right even though the current draw would be negligible switched power is the common procedure on all vehicles that I have seen.
Tony
I am happy to say I used a switched source. I successfully replaced every wire in the entire car except the dome light wire inside the roof liner and the temp gauge works.
Hello 29Red4,
When the sender at the engine is cold, does it still conduct voltage to the ground connection? If it doesn't, maybe the wiring diagram is accurate.