My gas gauge does not want to read correctly

BYRDE5

MEMBER
1982 CHEVROLET TRUCK

I bought this truck about a year ago and I have had to make the usual repairs to any used vehicle. I've done well except now my gas gauge does not want to read correctly and its blowing my mind. One day it reads fine the next it either shows empty or a half tank past full (the needle is maxed out to the right) lol. Which first came to my mind possibly the wiring. Here is what throws me for a loop. When the engine is running and I am rolling, if I push in the clutch the gas gauge jumps back to empty. I let off and it throws its self all the way to the right again to full. Of course if I hit the brake the needle quickly drops but at a stop it goes back to full. So is it the wiring or the sending unit shorting out?

2 Replies

NITESPOT

MEMBER
6 POSTS

Sounds like a wiring problem. These are always fun. You probably have a couple wires that have rubbed through their insulation. I don't know if you have a repair manual for your vehicle, but I would get one. Usually in the back of the manual there will be some wiring diagrams. Check to see if any brake and clutch wires run nearby the fuel sending unit wire. It will also tell you what color wires you are looking for. Then it's just a matter of following the wires to the wiring harness and checking to make sure all the wires are in good shape. It sounds to me though that you're getting some stray voltage/ground continuity from another circuit into your fuel level circuit which is causing the funny readings. Just be thorough and take your time to check all the wires.