Just noticed last night that when i open any door the interior lights don't come on. They will work if you turn them on but just not when the door is opened. Any help would be great.

 

Do they not come on when any of the doors are opened?

 

i can open any and all doors and nothing happens. also if i have the truck off headlights on and open the drivers door no dinging.

 

check ALL the under dash fuses, there are ones that effect multiple circuits.

 

I had this exact same problem and here is what I found. Nothing. I never was able to figure it out and just gave up. I have bigger fish to fry right now. I took apart the switch at the door and cleaned it and put it back together as well as the light. Nothing fixed it. It may be that my door switch is bad and could be your problem also. As was already said, start by checking the fuses. Let me know if you figure it out. Good luck.

 

Just found out because the lights don't work the rear wiper and defrost wont work either. Whats next to do? pulled all fuses and none blown cleaned/checked all door switches.

 

There is a procedure for testing your multifunction unit somewhere on here...ah:


Diagnostic Procedure
1. Close all doors and the tailgate.
NOTE: If the oil pressure switch goes open circuit
(engine is started) during the following procedure,
the MFU will exit the diagnostic mode immediately.
2. Press and hold the heated rear screen switch
and switch on the ignition.
3. Release the heated rear screen switch within 2
seconds and the MFU will beep to indicate that it’s in
diagnostic mode 1.
4. Press the heated rear screen switch; the MFU
will beep twice. In turn, operate each of the following
switches, heated front screen, rear fog guard lamps,
side lights, headlights, front wiper and rear wiper.
The MFU will beep twice each time a switch is oper-ated.
5. Pressing the heated rear screen again will cause
the MFU to enter diagnostic mode 2.
6. The MFU will provide outputs to the following in
order given below:

Heated rear screen relay energised for 2 seconds

Heated front screen energised for 2 seconds

Courtesy lights energised for 2 seconds

Dim dip relay energised for 2 seconds

Rear fog guard lamp energised for 2 seconds

Headlamp power wash energised for half a second

Front wiper energised for half a second

Rear wipe/wash energised for half a second
7. The MFU will then exit the diagnostic mode.

The test should tell you if it is ok or not.

Also check all of your door switches....

This is the control box on the back of your fuse box. I lost my defrost and rear fogs. There are a lot of things controlled by the MFU.

That said, your defrost and rear wiper will not work if the truck thinks a door is opened. Also, if a door is open for an extended period, the light will shut off. If you have a bad door switch, it will cause all of what you are seeing. I would take them all out carefully and test all of them, including the rear door.

 

Multiple symptoms point towards the MFU, so using the diagnostic above may tell you something. After not being driven for 10 weeks my MFU showed similar symptoms, but then suddenly started working again. Of course it started working after I purchased a replacement MFU, so I have one available if you need it.