wiring issues

some weird stuff going on, was having fuel gauge problems where it was reading past full 3 o'clock, i fifgured out the wiring on that. I t will read correct when no headlights are on, now when i turn the headlights on it goes to the 9 o clock position. why would the headlight's do anything to the fuel gauge?

also the flashers work but can not get the turn signals to work left or right. I replace the turn signal switch in the steering column no luck there.

not a daily driver a project truck. maybe wiring harness needs be replaced completely but it looks fairly new.

Sounds like grounding issues. Stray voltages do all manner of weird things.

The flashers and turn signals are separate circuits. Check your signals at both sides of the the comb connector in the steering wheel.

bad flasher? there are 2 one for signals other for hazard.

flashers are good. some funky wiring going on, the previous owner rigged the ignition where the key is only to unlock the steering wheel. ignition switch is mounted to column. also wired a kill switch. guess will have to let the pros take a look at what's going on.

Any responses appreciated!

Jtobe81 said:

some weird stuff going on, was having fuel gauge problems where it was reading past full 3 o'clock, i fifgured out the wiring on that. I t will read correct when no headlights are on, now when i turn the headlights on it goes to the 9 o clock position. why would the headlight's do anything to the fuel gauge?

also the flashers work but can not get the turn signals to work left or right. I replace the turn signal switch in the steering column no luck there.

not a daily driver a project truck. maybe wiring harness needs be replaced completely but it looks fairly new.

Click to expand...

Sounds like a bad or lose ground wire between the battery ground and the core support small 10ga wire.

That looks horrible, I think a dash harness is available. If not how about a salvage yard? Probably would be better off pulling it all out and starting over rather than chasing various electrical issues.

yeah I don't know what the idea was with that. The wiring actually doesn't look to bad might be fairly new. yeah what a pain trying to chase down wiring!

Check your grounds (as others have said). As I was working on my "new" truck, I was replacing ground straps as I found them. The +43-year-old straps were mostly corroded and had bad/dirty connections. My cousin was chasing electrical gremlins for a few years on his 2000s Yukon; it turned out to be a single broken ground strap. I had issues with one of my old bikes years ago - started adding grounds, as per a suggestion from a bike mechanic buddy, and the issues went away.

Trying to think where a fuel gauge would cross with the headlights, and the only thing that comes to mind is the printed circuit behind the gauge cluster. Start there, any thing shorting should be fairly obvious.

The previous owner may have added that rat nest to bypass an existing problem. You won’t like it, but probably need to start by getting the whole steering column down to bare bones. The ignition switch might be the first thing to look at as it’s the hardest thing to get to and the most likely culprit he was trying to bypass. If you have the dash out, you may be able to reach it from the top. From the bottom, you are going to have to unbolt the column from the firewall to drop it down a few inches to get it off the top of the column. And while you are there, replace every single switch you can from the high beams, turn signal, wiper, ignition, revers/neutral safety even the horn. You will never want to do that job twice.