2002 F350 door ajar issue...

[L9000]

Ok so here's a weird one. Friend's 2002 F350 has had multiple different things going on. It had a door ajar lamp on, but no dome light operation, etc. Plugged in my IDS and determined the CSM (security module located on firewall above trans hump) was faulty. Has no communication with the old CSM, no door locks, no keyless entry. So I replace the CSM with a new one, reflash to latest calibration, and reprogram key fob. I tested everything, and now the door locks work properly, keyless entry works, but now I have an odd door ajar issue...

While monitoring the datastream for all four door ajar switches, I noticed the two front door switches are showing "ajar" when shut, and "closed" when open. So I replaced both door switches, still had the same problem. Inspected the door latches, and found them to be full of sand and debris. Replaced both door latches, tested everything again, and still have the same issue. Dome light on when doors shut, off when open. Also, the delayed power to the radio, etc stays on until I shut the driver's side door. Basically, everything is working the exact opposite of how it should. Rear door (crew cab) switches always display "closed" via CSM datastream regardless of if they are open or closed. Dome light always off when rear doors are open or closed.

I scanned the CSM for active codes, and found B1330 "passenger side door switch short to ground" fault set. Code is reset as soon as it is cleared. However, I inspected all connections for this circuit, and found them to be ok. Removed and tested all door ajar switches, and found everything to be good. Tested for resistance between the passenger side door switch circuit and gound, and found no continuity present (no short to ground). Also tested between the switch pins and the switch body, and found no continuity present. Tested for correct 12V+ and ground signals at the CSM connectors, and found everything to be good. Checked for proper wiring pin placement in each of the three CSM connectors, and found everything to be where it should be.

I have swapped in a known good CSM from another 2002 F350 crew cab, and it changed nothing. Installed the new CSM from the offending truck into the other '02, and it worked fine. Do not suspect a bad out-of-the-box CSM.

So now I am starting to wonder where the problem lies... My next thing to look into is a failed GEM or possibly a fuse box assembly. I am running out of things to check. Hoping it is not a failed cab harness, though anything is possible. However, if it were a failed/shorted harness, you wouldn't think the operation of the front door ajar switches would be "inverted".

So here's the question, has anyone ever run across something like this? And if so, what was found to be the culprit? Seems to be when they changed electrical systems in '02, that's when all the problems started.

Please don't start off by saying "spray a bunch of WD40 into the latches." Thats not the issue, all latches/switches are new.

Any/all help is much appreciated. Thanks!

[Codum]

I had issues with my 02. Did you try it? The WD40 that is! That's what fixed mine. I know sounds like you have another issue. But, did you try it?

[L9000]

Originally Posted by L9000

Please don't start off by saying "spray a bunch of WD40 into the latches." Thats not the issue, all latches/switches are new.

.....

[510guy]

has anything recently been added to the truck?