M38Cdn Refurbishment

[Peter Phillips]

Originally Posted by rob love

You are lucky they work. I found that usually on those gages, the fuel in particular, as well as the temp and oil pressure, would burn out without a ground.
The later M-series added a short ground wire from the panels to the dash which helped prevent this. There are times that you have the dash backed out (cable or gage replacement) that turning on the ignition switch can have bad results.

Same goes for testing gages on the bench. You must provide a ground to the case or the negative stud before applying power and sending variable negative thru the wire.

Interesting Rob, never knew that bit of info...thanks . I haven't tried the fuel gauge but the ammeter, oil pressure and temp works fine. Interestingly I don't remember seeing a ground symbol coming from anywhere on the dash....unless I missed that?