Headlight trouble

You have two headlight relays. A left and a right side. The only way they can both be energized is if your turn signal/highbeam switch is shorting out. I doubt a wire short would short across three wires.

If the headlight switch was shorting I would think just low beam would stay on.

 

Check the headlight relays/breakers. They can corrode on the inside.

 

I'm looking for a wiring diagram now. What's the year and model?

You could unplug it and take an ohm meter and check across the "hot" and the feeds to the relays on the switch.

 

it is probably a bad ground, had the same thing on a kw, grounded and all is good

 

I'm having trouble finding a diagram with the wiring colors.

What you can do is leave it plugged in, and back probe (stick the red probe point through wire insulation or backside of connector pin and ground to chassis ground) and look for 12V DC. With everything off there should be one HOT wire (red) and if it's shorting two more wires will be hot.

Note them two wire colors on the switch side. Then unplug the harness and use an ohm meter across the HOT and each of them other two wires one at a time. That would tell you there is a short for sure.

There are little copper contacts in that switch. One can break and it falls and lays across other contacts creating a short.



You can also inspect the relays for corrosion but I doubt they would both be bad at the same time. It's in the relay panel under the hood.

Your turn signal switch/high beam should have two connectors on it's harness, some four. The connector with the most pins is the one you want to look at.

 

Staying on or off?