Reviewing the service manual for my car, under gauge testing, they showed a little tester unit being used. It was a round can with a dial on it. I am assuming it is some kind of voltage reducer so you don't blow the gauges. It had its own Chrysler number and name.
Anyway, is there some way a person can make something like this, or some sort of shade tree trick to reduce voltage. I would like to check all my gauges while I have the cluster out.
neal