I have a 2003 Excursion 7.3 2WD Limited and all of the sudden experienced a number of issues all at once.

1. Turn signals stopped flashing (hazards still flash)
2. Lost Rear back up sensors
3. Lost overhead trip computer
4. Lost Rear A/C - switch does nothing
5. Front A/C now only blows through the defroster vent

I've checked all the fuses and cant find any bad ones.

I replaced the multi-switch flasher and turn signals still dont work - only hazards.

With all these things happening at once, I'm hoping someone can help lead me in the right direction before I go crazy -

Thank you -

 

Sounds like your BCM is getting wet. Look under the dash outboard of the pedals and see if theres evidence of water dripping from above. Your windshield may be leaking. Common issue.

If not, the only other thing I can say is make sure you have no vacuum leaks and your vacuum pump is still working. RE, defrost only issue.

 

Thanks for the advice. I looked at the BCM and I dont see any evidence of water (current or past) - I actually had the windshield replaced about 1.5 years ago.
I also visually looked at the vacuum lines under the hood and nothing really stood out -
Anyone elses advice would be welcome.
Thank you very much.

 

OK - so I had more time today and after troubleshooting, I've narrowed it down to fuse #27 that keep blowing as soon as I shift into reverse.
Prior to shifting, everything works as it should -
I unplugged the rear sensors, back up lights, trailer plug, and each time, fuse #27 keeps blowing.....
Does anyone have any other suggestions on where I should look?
Also - if anyone has a 2003 excursion wiring diagram that shows what all fuse#27 controls, I'd really appreciate it!
Thank you -

 

I found this from you owners manual (an electronic copy is in the tech folder):

Fuse 27 is a 15 amp fuse and is label as: ignition switch run feed

Not sure what all would be connected to that though. Sorry I can't be more help.

 

I am not sure I can help on this but I am having similar issues and have finally made the issues stop to just two things. My issues started when I hooked a trailer up to the truck. The next time i tried to start it would not start. I thought I just drained the battery. Used a jump start battery charger and it started right away. But noticed in order to turn on lights I had to turn light switch off, and radio would not play unless in drive. This happened for many times. Only way I could get truck to start was with a jump box or another running car.

I have replaced starter, battery, and all relays. The alternator is putting correct amperage out. I unhooked battery for a time and now it starts every time but the radio and windows will not work.

A guy at work suggested the GEM, but I can not find one in my 2003 with the V10 engine. When researching today I found a blog that stated it is behind glove box but then also read the 2003 does not have a GEM.

I believe it seems right that this could be the issue (Computer issue) but what is the computer module that would need to be replaced to correct. All relays and fuses are good.

Any help would be great. Don't want to hijack thread but very simlar issue.

Thanks, Brian

 

Check your gear shift lever wiring. Put the truck in neutral (block wheels) and install a new fuse. Shift into drive and see what happens.

 

I agree with JP38057. You most likely have a rub. A wire moving against something metal every time the shift lever is moved, eventually wearing through the insulation and now shorting to ground. I've included two PDF's of the wiring for an 02 X that may help you. Wire feed in a lightblue with a pink stripe (LB/PK). You have to take the cover off of the steering column. The plastic shroud covering the key switch pulls off (snap on attachment). A word of caution. You may want to disconnect the battery and wait 5 mins for backup power supply to bleed off before starting to avoid accidental discharge of the airbag.

 

You sir just got smacked with a rep hammer for directing someone to the tech folder!

If it is the gear shift lever shorting the wire in the steering column, directions and pics on how to tackle that problem are also listed in the tech folder sticky thread.

Stewart

 

Red herring. That would be fuse F45 on his truck, not F27. Ckt # 295 doesn't go up the steering column any further than the shifter interlock. See the diagrams Scarmandos posted for F27 distribution.


I assume that means you're shifting from PARK to Reverse. Have you tried starting in neutral and shifting to DRIVE to see what happens? If it doesn't blow, shift from neutral to reverse and see if that pops the fuse. If so, then the problem is isolated to the reversing lamp (and associated) circuit. See cell 93 in the EVTM for that circuit.

 

Thanks for all your help.
The fuse only blows when I specifically shift it into Reverse.
I can start it and shift straight thru to Neutral, Drive, 2, 1 and everything continues to work just fine.
Figuring it was specific to reverse, I tried disabling the rear sensors (unplugging them under the back bumper), then the back up lights (pulling one bulb at a time), unplugged the Trailer plug.

 

Unplug the reverse sensor module. That is what controls the sensors in the bumper. I think it's in the right rear corner of the truck.