Neil F85

The fuel gauge on my 64 Olds sits on empty except when I add gas. Then the gauge registers correctly. But when I shut off car the gauge goes back to empty and sits there. Sometimes if I tap on dashboard plasticthd gauge movesto correct position. But then it goes back to empty. Any suggestions would be appreciated.

jaunty75

You are worried about nothing. As long as the gauge reads correctly with the ignition ON, everything is fine. There is no power flowing to the fuel gauge system with the ignition off, and the needle can come to rest anywhere. What the gauge reads with the ignition off is meaningless. Go have a beer and watch a baseball game!

Neil F85

Took your advice. Watching game. Thing is gas gauge sits on empty when engine on. Sometimes it moves to correct level sometimes it just sits there. Back to the game. At least my team winning.

oldcutlass

What you describe is a bad or corroded connection somewhere.

jaunty75

Your first post did not make this clear.

The gauge sitting on E all the time indicates a short circuit in the gauge wiring. The sending unit is just a rheometer where full is 90 ohms and empty is 0 ohms. But a short circuit would also be 0 ohms. If the gauge moves to E intermittently while driving, it's time to hunt for an intermittent short.

The standard first tests for fuel gauges is to separate the wire running from the gauge to the tank in the area behind the license plate as that's where the wire from the tank and the wire from the gauge connect. Ground the side coming from the gauge and turn the key on. The gauge should go to E. Then remove the wire from ground, and the gauge should go to F (or, often, well past it). It sounds like, in your case, the gauge will not necessarily go to F. If it doesn't, then there is a short, or intermittent short, in the wire from the gauge to the rear of the car. Perhaps it's pinched somewhere. The fact that you can tap on the gauge and get it to read correctly (as I said, it was not clear in your first post whether you were doing this tapping with the ignition on or off) suggests a possible problem with the dash gauge.

If the gauge passes the tests above but you still get the intermittent E reading, the short is in the sending unit.

If you don't have the 1964 Olds chassis service manuals (it was a 5-volume set that year), you should get them. There is a full gas gauge troubleshooting section in there.

https://www.ebay.com/itm/1964-Oldsmo...QAAOSwv5Nc2kT8

Neil F85

Sorry for the confusion. Shutting off game and getting to work. Thanks again. Yes I have those manuals. I'll look them over.