2002 Fuse box/ Harness issue

[mudmonger]

I have a 2002 XLT and have recently had some very wierd electrical issues. It started with the temp readout in the dash being off about 30 degrees (probalby sensor). Then when I lock the doors with the remote it honks twice at me like something is unlocked, but its not. Next the AC clutch stopped engaging all the time. And when I would try to run the AC, after about 15 seconds the fuel gauge drops to empty until the AC has been off for about 15 seconds. The last thing to happen is that the wipers front and rear don't work at all now.

So............ I took it to the dealer so they could scan the computers and they told be there is a wiring issue under the main fuse box in the engine compartment and that the harness around it is attached. This means a part that is $2400 to buy and $1100 to install. The vehicle is barely with this in trade in value, but is payed for. I don't mind changing the harness if I have to, but does anyone here have any experience with these type of issues or changing the newer harness out? Thanks in advance for any help.

DMC

 

[mudmonger]

Update

Well, I have started looking for a harness. A local salvage yard (one of the better in my area) sent me packing. They didn't feel they would have a juction box (fuse box) that had it's harness intact. I was bummin and decided to go home and do some testing of my own. I had the entire fuse box disassembled, as far as I could with out actually pulling clips that hold the wires in. I measured everything on the A/C circuit I could and found no gaps. Everything also looked to be intact and corrosion free in the box. I put it all back together and decided to test all the grounds (found 4 around the motor compartment) and the A/C plug at the compressor. All the grounds seemed to be OK- did get a couple of mili volts on most while running. Also found power at the connector with A/C on. The dealer said there was no power to the A/C circuit, but here is 13.8 when trying to engage. I didn't test the ground side though. I also noticed that when turning the A/C on with the connector out of the compressor that the wierd dash tricks were gone. I will now test the ground side to make sure it is intact. Has anyone ever heard of a short in the compressor itself? Right now I don't believe I need a harness and fuse box as much as finding a couple of shorts or open grounds. I will be talking with the dealership Monday. I don't think they did a very good job of trouble shooting this problem.

 

[rrgone]

Hey man, welcome aboard. I know this is gonna sound weird, but how long have you had your battery? Is it OK and the charging system up-to-snuff? Very strange electrical stuff is known to happen when the battery and/or alternator are on their way out.

 

[mudmonger]

Update

I am not sure on the battery. It was in the vehicle when I bought it 2.5 years ago. The alternator has not given me any problems either. When testing yesterday I got 12.6 volts from the battery when the vehicle was off and just under 14 (13.98) when it was running. These numbers seem pretty good to me. The only problems I have had are as mentioned in my posts. If I have more time today to test anything I will update again. Thanks for the reply.

 

[rrgone]

You might try a reset. Unhook the battery ground clamp for about 10 minutes. Make sure the clamps are both clean and snug on the battery posts.

 

[mudmonger]

Update

I had the negative terminal unhooked yesterday for about 3 hours while I was going over the fuse box and 2 days before that it was unhooked for about 2 hours while I removed the instrument cluster. Still have the same condition. I am going to check the negative side of the AC compressor today. Am I correct in assuming that one side without voltage on the clutch connection is a ground? In therory, if I am right, I should be able to connect directly off the battery and it should run. If it doesn't, then wouldn't that be a bad compressor? I will going after the wipers in the same manner after I learn a little more about the AC compressor. Another thing I noticed, but have not tested anything yet, is that with the key out the ignition the door lock switch in the drivers door does not work. With key armed this switch does work. The passenger side switch always works. I have not tried the rear hatch lock switch yet, but found this interesting. Thanks again for the reply.

 

[jrford]

'sever heard of a short in the compressor itself'

yes on my heep, keep blowing the cruise and A/C circuit. I also noticed around the clutch a lot more rust then usual, i think one of the winding wires broke lose and was shorting out.

 

[mudmonger]

Update

If I were to ground the compressor to the chasis seperatly and then engage the power to the compressor it should work unless the compressor is shot. This would rule out a ground issue wouldn't it? It would appear that everything else in the AC circuit is good since the 13.9 volts shows up every time I turn the AC on. If the low pressure switch was tripped or something else was shorted the power should never make it. That is, if I understand this correctly.

Also, I think my door switch problem may be the central securtity unit. The door locks fine as long as the key is on. Neither the lock or unlock work from this door with the key out of the ignition. Both the passenger door and hatch work fine. I can not see anything in the wiring diagram at the switch that would cause it only work with the ignition on. Wierd?

DMC