Heya folks, been awhile since I've needed to look for anything here, but I'm back now.

Just brought home a 2003 F150 Super Crew for the gf. She loves the hell out of the truck but after getting it home I realized we have a couple issues, and I'm betting they're all related.

We have front parking lights but no taillights (brake lights and reverse yes, taillights no. No power at all to the sockets) or license plate lights.
We have no horn (fuse is good and relay clicks, horn could just be dead though. Had it happen before).
Key fob and door buttons unlock the locks, but do not lock the locks.

I also found a CompuStar CM4200-VD for which there was no remote, and an iDataLink ADS-TB (16).

I've unplugged both modules, truck still starts, everything works, but aforementioned items still exist. My plans this weekend are to completely remove the wiring for both items, and hopefully I'll find that the problems are due to a broken wire or something similarly simple.

In the mean time, does anybody have wiring schematics for the lights and locks for this truck?

 

the tail lights, brake lights, have different fuses. look in operators manual or diagram on the fuse box.

I had some sort of "anti theft" system on my 2002 when I bought it. Problems with the FOB because it wanted you to use THEIR remote. Worked OK after removal of all.... They cut a couple wires to the ignition switch and spliced into it.. I had to lay on drivers floor and cut it all off, then splice a couple switch wires back together. All was good after that.

 

Yeah, before I found the modules, I was looking through the fuse boxes to see if the taillights were on a separate fuse from the front lights. Didn't find anything. I'm hoping that when I get everything removed from the truck I'll find that its a broken or spliced wire.

After that, maintenance!

 

The remote system shouldn't affect taillights. Check for corroded or damaged connectors from the cabin rearward, usually around the spare tire.

 

Pulled the rear harness out of the truck, found that one of the previous owners really needs his godd*mn boogerhooks smashed with a hammer.

The taillight side of the harness was cut, lengthened, and patched twice in the same area. Both license plate light sockets were replaced and molested again. And rather than simply plugging in a Hopkins 4/7-way bracket, they cut the plugs of the Hopkins piece and the taillight harness and spliced those together as well.

I'm guessing the same mouthbreather is the one that screwed 2 different trailer lights into the bottom of the dash for redneck underglow. I've found multiple small screw holes where a toolbox was screwed to the bed rails, pair of CB antenna mounts, screw holes where the CB was mounted on the black plastic below the center of the dash, and while they had decent taste in what they bought for audio components, they wired those like a blind retard as well.

For right now, I'm going to try to just patch up the harness so we can drive the truck, but I'm looking for a replacement. This is some bull*****.

 

Does your cruise control not work either or is it just the horn? If neither work, it's possibly the clock sprink that's under the steering wheel. It becomes seperated if any severe stress is done to the steering. If your truck doesn't have cruice control, ignore me.

 

Horn fuse is good and relay clicks. I'm betting on just a dead horn. I've had it happen on other vehicles, including my old F250 diesel. I'm gonna pull a horn Monday when I grab the harness.

 

Ok, got the taillights all working, replaced the harness with one from another truck. Still haven't replaced the horn, just haven't been to the yard to grab one.

Locks suddenly started working today, and just as suddenly, they stopped working. I don't know if it's a loose wire or if it really is my switch (which seemed to test good). I started wiggling the wires under the dash, the harness for the remote start, all of that, got no response back. Where do I start looking? Really wanna have everything working and I'm not familiar with these trucks.

 

Bueller? Bueller?

 

Ok, I guess I'll ask this a different way.


Any chance I have a problematic body control module?