Weird cluster light issue

[tybach]

Hey guys, been lurking for a few months and have really appreciated all the info here. I recently purchased an '83 720 and have the weirdest issue with my cluster lights.

When the switch for the headlights is in the off direction, the cluster lights are on and the cig light is off. When I turn the headlights on, the cluster lights go off and the cig lights goes on. It sounds like there is a wire swapped somewhere but I can't quite figure out where. I disconnected the dimmer switch because it wasn't doing anything at all.

Any help would be greatly appreciated!

-Thanks

[dayid]

I'd say to fix the potentiometer for the dimmer first before you go chasing other things around. I know your '83 interior is different from my '85 a little, but it is easily accessed by just removed the beneath-steering-wheel metal plate.

[PEZi]

Don't go fussing around with it too much. Stay close to home with the cluster. Just remove the cluster and search for broken or crossed wires to start. With the age, it is certainly possible.

[tybach]

I did clean the back of the cluster a few days ago and the gas gauge and temp gauge are now working but the gas gauge isn't quite accurate. I'm going to take apart the dash hopefully this weekend and see what I can find.

[PEZi]

Gas gauge in these are never quite accurate... It is float based in the tank and depending on if you are on a hill, accelerating, braking etc... it will always read different

[tybach]

Should I drop the tank and see if I can play around with it? I'm a little more concerned with the cluster light and if I have the time this weekend I plan on taking a look. I was thinking it could be my steering light switch.

[PEZi]

Stick with the light for now. The gas thing is common and won't actually hurt your truck at all.