Alright I don't know where to start so I'll just spill it. '99 S10 PU 2WD RC SB 2.2 5SPD.
All problems seem to be rear passenger side.
Lights on, all good.
Lights on + reverse = No passenger reverse light, no passenger license plate light.
Lights off + reverse = Reverse light on license plate light on.
Lights off + drivers side blinker = All good.
Lights off + passenger blinker = Blinker blinks with license plate light.
Lights on + drivers side blinker = all good.
Lights on + passenger side blinker = Blinker blinks with license plate light / both blink fast.
I removed rear harness from truck and stripped of all the loom. I inspected the wiring, found nothing. There is only one ground for the entire rear harness, it's good.
I did find something on on the drivers side blinker socket. It looked like it got hot at one point. Someone spliced in some wires there that I assume would run a third brake light on a topper. I removed the wires. That socket always worked and still does.
Re-wrapped the harness and reinstalled it. Nothing has changed.
Is the problem with the blinker switch or what? I'm out of ideas.
P.S. Does anyone know what those odd looking connectors on the rear harness are for? I can't imagine what they'd ever be used for.
Thanks for any help,