Packard Forum Index » V-8 (1955-56)

Packard Techs,
1956 Packard Patrician.
My gas gauge and temp gauge to go the right when car is started. This started after changing window motor on drivers side.
Any suggestions?
Packard56

The window circuit and gauge circuits are in separate looms. They normally do not share any fuse or signal so something must have been moved or possibly hooked up to an incorrect spot to have a window issue affect the gauges.

On a Patrician the oil, gas and temp gauges all work off an instrument voltage regulator which regulates the 12v battery voltage down to a pulsing 5v which feeds the gauges. The regulator is screwed onto the back of the cluster and must be grounded for it to work. If it failed or came ungrounded that could cause the issue but assuming the oil gauge is working it too should be moving to the right if there was a problem in that section. Can you confirm the status of the oil gauge.

A grounded signal in the wire from a sender would cause the issue but the various gauges all have independent wires out to their senders so not likely two wires would be shorted unless something happened behind the dash or in the engine compt when the car was being worked on. While not likely, those two gauges are on the top side of the cluster so could something have moved or fallen and shorted or damaged something at the cluster or in the section of loom heading out to the engine compt.

The gas gauge wire to the tank sender passes thru a plug located behind the drivers side kickpanel and then down the loom on the floor to the trunk. The temp and oil sender wires go straight out the loom behind the cluster and into the engine compt where the temp sender is near the firewall behind the left head and oil sender is at the top rear of the engine. Those two wires exit the loom at the rear of the engine and might be fairly close to one another so could something have pinched the loom and shorted the wires.

G'day Joe Krzan,
First post, but see you've been a Forum member since 2016, so to PackardInfo.

I invite you to include your '56 Patrician in PackardInfo's Packard Vehicle Registry.

As Howard points out, the ground is likely an issue with both. gauges that I have had a similar problem with had dropped the ground connection and without that, they were "pegged" to the right.

Joe, when the car is started, or just when the ignition is on?

An instrument cluster voltage regulator that fails with the contacts shut will spike the temperature and fuel gauges to full scale...

...the gauges barbecue inside if that is allowed to go on.