Hello,

I have been trying to figure out what's going on with my fuel gauge also when my door is shut that the clock is the only lights that work. If the door is open the other lights work on the dash. Also when my low beams are on the high beam indicator is on. So what do I need to do to fix these problems? I tried cleaning the connections on the tan wire in the tank and took a test light to the gauge as it goes down to the hot side and got it to a 3/4 tank when I had filled it completely. So any help would be greatly appricated.

 

Gas gauges are notoriously fickle. The fact that yours works at all is impressive.

For the light issue, first I'd also check to see if the pin connector on the driver door is grounding out. When you open the door & the dash lights go on is it the driver's door, passenger door, or both that you are opening?

The next thing I'd check is the panel ground strap. Because it's not all the lights that are out (the clock is still on) my bet is it's the ground strap and the lights are seeking ground through the door light circuit when the courtesy lights are on.

It's possible that both problems are related to ground issues. The ground isn't a wire (if I remember right anyway). It's a sheet metal strap that goes through one (or a couple) of the fasteners that hold the plastic dash into the metal part.

 

I don't know about the passenger door as I don't normally have it open that much I just know when the driver door is open they all light up and when it shuts they all go out. except the clock

 

First thing I'd do, is check all the ground wires and make sure they're connected to clean terminals. Especially the two from the body to motor, and the one from the negative battery cable to core support!
Check and clean those, and see what happens.

 

I just checked out the wires for the doors it appears that the driverside is attached to the headlight switch is that correct? I also checked to see if the passenger door open or closed made a difference and it didn't it appears to be driverside only. It felt as though there were two wires from the driver side door terminal. Could it be a bad headlight switch? If so how do you remove it? Thanks

 

I checked those two terminals and sanded on the mounting area and remounted and still the same issue. How many other ground straps are there and would it be best to pull the dash completely apart to get to them or what would you recommend? Thanks

 

There is a white wire that connects to the light switch that wire grounds out on full CCW rotation of light switch **** if you don't have the wiring diagram I have it for 68-69 Cutlass on a PDF file which I can email , PM me your email address and I could send it to you

 

Thank you for that wiring diagram and I'll see if I can figure it out and if anyone else has some ideas that would be great. Thanks

 

I have noticed if the headlight switch in a certain spot it stops the fuel gauge from going up or down that's with the door open could the switch be part of my issue or maybe a ground connected to it? It's difficult to really see up in the dash as my dash is somewhat together.