Fog light madness—everything works opposite how it should

Ok, TW. I’ve read just about every post on fog lights there exist and I haven’t seen anything that helps my issue. I’m sure there’s someone really smart here that will read this and know the solution right away.

Installed aftermarket fogs yesterday. ‘09 Prerunner, no OEM lights, but pre-wired for it.
After getting lights, relay, and switch in place the lights work…ON HIGH BEAMS ONLY. It will come on with the parking lights, but once low beams come on—fog lights go off. Switch to high, and the come back on. Obviously, this doesn’t work for me.

I tried doing the anytime mods with equally mixed results. Splicing into the light green wire, fog lights only come on when the lights are off when the ignition is on and vehicle is running. When vehicle is off, or just in ACC, it works perfect. But when you start the truck, when I switch the lights on, fogs switch off. With the other method—rigging to the trailer relay, it doesn’t work at all.

I’m at wits end. Should have been a 10 min project and has turned into 4 hours. I’m sure someone knows what’s wrong.

 

Since I don’t know exactly what parts you used, I’d make sure the OE wiring is correct first.
Start by pulling the Relay and checking the terminals. Be careful and don’t jam the test light or meter lead in to far. This could cause the terminals to open up and be loose later. Just touching is fine.


Pin #1 should have power with the Headlights on LOW, and NO power on High.
Pin #5 should have power at all times from the Fog light fuse.
Pin #2 should show GROUND with the Foglight switch ON, and Open/Nothing with it off.
Pin #3 Goes TO the fog lights. No need to check it on this test.