'04 Low beam not working....

[RWlRAM]

So I've been getting a lamp out indicator for some time and if I turn the headlight switch on and off it goes away and doesn't come back for awhile.
I've checked the lights multiple times and all seems fine when I've checked.

Today I decided to look into it further to try and determine what was going on.
So when I look, the right low beam was out so I fought with changing the bulb and still no low beam.

I tried to check the voltage but all I got was 3.59v or so on each of the outer terminals on the socket and 0v on the center, obviously the ground, all measured to the frame.

I admit I don't understand the "BUS" system, but to me if the lamp lights the sockets should read near 12v.
What am I missing?
I can read a conventional schematic but the wiring block schematics are a PITA.

So after burning the eyeballs in the Service Manual for an hour + I decided to just let it sit and button everything back up and put things back together.

I turn the key to move the truck out and no "Lamp Out' light.
I go out and check and the friggin' light is now on.

Through venting, but if anyone has a guess to what was / is going on feel free to throw out your 5¢ worth.....I'll take it!

 

[Hanover Fiste]

Sounds to me like you had dirty contacts on the lamp socket.

 

[kevkev]

I had no lowbeams and it was the TIPM. I had it rebuilt. Problem solved.

 

[RWlRAM]

I replaced both the IPM and the pop tart FCM in 2019.
The IPM was from https://tipmrebuilders.com
I got the FCM from the local Pick-A-Part.
I bought the truck used at 113K and know it was in at least one maybe two accidents in it's previous life as the left side shows evidence of repainting.
It's working so I'll leave well enough alone.