'72 Rallye Gauges

[moparone72se]

New here. I've owned my 72 SE since 1988 and never any issues with the gauges. Coming home from a show this weekend the gas, oil press and temp gauges suddenly peg all the way to the right. I stop to check wiring and find no burnt wires. I drove rest of the way home and checked that the gauge cluster wasn't getting hot. No burning smell or anything. I would think being "pegged" like that they would get hot and melt stuff.  I figure the voltage limiter, but want to be fairly sure as I don't like the thought of pulling the cluster. I did put a new temp sending unit in (last summer) and it quit after a very short time. But it came to life and "pegged" out also. The gas gauge went to "E" first and then "pegged" to the right. Got home, pulled the battery cables off. Had this car too long for it to burn up. Thanks for any help.

[Pete in NH]

Hi,

Welcome to the group.

With all the gauges pegging, I would suspect the instrument cluster voltage regulator as you've already guessed. They commonly fail by welding up their contacts and putting the full 12 volts on the gauges. This will quickly burn out the gauges, so you are right not to run the car until the voltage limiter is replaced. RTE Engineering makes a transistorized replacement unit or you can use the original electromechanical type. I would use the RTE unit. There are also many plans on the internet to replace this regulator with a 7805 electronic regulator from Radio Shack. Do a search on Mopar instrument voltage regulators.

[ACUDANUT]

 Good info, I heard Radio shack went tits up.

[Pete in NH]

Many, many Radio Shacks did close so they are not as easy to find as they once were but, some are still in business. If anyone wants to go the 7805 voltage regulator route, they are readily available from many sources such as Mouser Electronics at mouser.com   I'm sure you can find them on EBay as well or with an internet search.