Hi,
I just bought a new to me 06 xlt 4x4. The guy I bought it from said the wiring was screwed up(power windows etc didn't work)when he got it, he's an electrical Mechanic or something and said he had it all figured out...
Couple of days ago I turned on defrost to clear frost in the morning and power windows, radio and some things in instrument cluster wouldn't work.
I figured out if I turned truck off, move indicator off defrost, lock truck with key button turning on security and than unlocked and start that all is good but as soon as I go to full defrost, same thing.
Power mirrors don't work anytime but Im hoping that's a fuse.

Does anyone have or know where I can get a wiring diagram to figure this out?
Thanks

 

I discovered it has nothing to do with defrost!
It happens in the morning when truck has sat all night. I discovered that when I hit the odometer reset button after truck has started it goes in the test mode and as soon as I do that, radio, windows etc work.

Could battery voltage be too low in the morning? it works fine all day after that initial start

 

It would be easy enough to drive over to a parts store and get the alternator and battery load tested.

 

I actually went to the shop at work today and had battery load tested, it's good.
I have a buddy that's a Mechanic, I think he's going to take a look at it Friday.

 

There's also been a intermittent brake light in the cluster I never thought much about.
While in test mode discovered the cluster was telling me my battery voltage was 11.3 for example yet my multi meter was 12.4 at the battery. Changed battery, same thing. My Mechanic friend who has the wiring diagram software on his computer, figured we should be looking at the cluster. Luckily he had an 07 f150 there he was putting a new engine in. We swapped clusters for a couple of days, everything was great. No voltage loss and brake light gone.
Called around for another 06 cluster was told there should be an ID number on mine 6l34 etc.
Mine started with 4l3f I think, Google says 04-05, Guessing not the original cluster, no idea how many miles are on it! Lol
It says 164,000 I honestly think its less, the 5.4 is pretty quiet, it drives tight, who knows maybe it was just well maintained.
Found another 06 xlt cluster at a auto salvage, should be here tomorrow.
Guessing an xlt to xlt swap shouldn't lose any chimes or Dome lights when doors open.