My auto headlights won't work the park lights and fog lights come on but no headlights. They work if you turn them to the normal on position. I had the truck into the dealer and they replaced the headlight switch. This fixed the problem for a couple of weeks. Then the problem came back.
I took it back in for two days and they said it started working but they thought the problem was that my amp was installed too close to the relay module behind the rear seat. The amp has been installed for over a year and a half. So I ain't buying that explanation. This relay module has at least 3 relays one for the fog lamps, one for the park lights, and one for the headlights. They said they will replace the relay module when it comes in. The lights are working tonight but the headlights did flicker a couple of times. Any one had this experience or have any ideas? How about a wiring diagram of this relay module and lights?

 

Think the relay will fix it!

 

I don't know. I would suppose that relay is used for manual and auto lights but the control that turns it on is probably were the split is. So hopefully replacing the entire module will fix it.

 

Dealer replaced the relay module and fixed my auto light problem. The first place I stopped the key fob would not lock the doors and the key pad wouldn't work. They forgot to give me the new factory code and didn't bother to progarm my keys. So I took it back and waited for them to fix it. Fourth time is a charm I guess. Not much follow through to check all of the functions of the module. That's the last time I go to this dealer.

 

Sounds like they replaced more than the relay module... ???

 

I was told the relay module has the relays and the radio control for the key fob and keypad and maybe more.

 

Interesting. I thought the remote code and the door code were keyed to a number that was posted on the computer.. or main processor.. but that could only be what the remote unit sensor will accept.. Interesting how complex this machine is and how much control the computer has.

Looking at the wiring diagrams confirms the complexity...

 

My auto headlights failed again while on vacation. When I got back took it back to the dealer for the 5th time. This time they spent some time (4 hours) troubleshooting the problem and fixed it. They replaced the multi function switch (blinker, high beam/windshield wiper stalk). Also replaced central junction box and last but not least repaired an open circuit?

I hope this is not a prelude to events to come.