I'm going insane trying to figure this out, and I've even got all the wiring diagrams in front of me from alldatapro! Here's what I've got.

I bought a 2000 crew cab off a guy about a week ago, and neglected to try out the headlights and such since it was day time. Long story short it's got some electrical issues and they are as follows.

interior dash lights don't light up, exterior parking lamps don't light up, power locks act like they're locking (As in make the noise) but don't move. Minus the rear passenger lock, it functions fine. Not sure if it's related or not but the climate control is stuck on defrost as well.

Here's what I've figured out so far. I can run a jumper from the constant hot on the headlight switch harness to both the parking lamps and the dash lamps and get them to turn on. The power window and lock buttons do NOT light up, but do light up any time I turn the truck to the on position. I can not get the warning chime to sound with the door open and the lights on. The headlights function normally with the switch, and the brights also work normally. I have tried a new headlight switch with no luck. When I first put the new headlight switch in and headed home there was draw on the trucks system, as in the volt meter was jumping up and down as I drove. I am assuming I have something melted or shorted somewhere, but I have no idea where they all connect. I'm still looking over alldata.com for it, but haven't turned up an area where all these things connect. Anyone have any ideas off hand? I'd love to avoid taking it to a shop already, but I'm about ready to break down and do it. The truck runs and drives fine, minus that issue with current draw. I hate wiring work more than any other thing on a truck...

 

Don't know that I can be of any help on your bigger issue, but maybe I can help on one of the smaller ones. Does your truck have Digital Climate Control? If so, the stuck on defrost, which is the default condition, is general a sign of solenoid failure in the head unit. There is a guy on ebay who has an exchange service on replacements. New unit from Ford is about $700.

 

Manual climate control

 

The climate control stuck on defrost is a saftey feature as the whole system is vac. controled, so in the event of a vac. leak the system defaults to defrost to keep the windows clear. If the truck is a 4x4 and is ESOF (Electronic Shift On the Fly) I would start by checking the vac. lines that go to each hub as they tend to get brittle and break/slip off thier fittings.

 

Ya might check down in the electrical forum, there's some good fellas there who know their stuff.

 

Running vacuum leak down in the AM. I found receipts for all the hub work already being done on both sides, but also checked them just in case, they look good. I'll try the electrical forum, didn't even notice it down there, haha.

 

I would check the dreaded wire in the shifter lever for the od. They are known to go bad and cause alot of problems. https://www.ford-trucks.com/forums/7...uestion-3.html

You might also want to check behind the fuse box for water intrusion, corrosion. It is a known area to also get wet when the windshield gets a leak. Known to create a lot of electrical issues also.

 

Everything looked good on the back of the GEM when I pulled it today. I also pulled it all out to check and make sure nothing was melted inside, and all was good. I'll check the column tomorrow for sure. Thanks.