Hi All- 2007 V50 here. It is my son's car and I have been trying to track down this issue- his driver window controls don't work for any window anymore, nor does the power locks. Hear me out- I've tried all the tried and true fixes so far, with no results:

1. I inspected the a-pillar power connector. I cannot see any problem wires there. I checked it for power and it is providing 12 volts. I also backprobed it.
2. I inspected the in-door wiring harness. Again, can't see any evidence of physical damage. I backprobed it after connecting to a-pillar harness and it is showing 12 volts. I also installed a used harness to see what would happen. Nothing. I then checked all the connections and I'm seeing 12 volts everywhere on the harness.
3. I got a used window switch, didn't make a difference.
4. I tried two different DDMs (used). Again, no change.

The switch itself does not appear to be getting any power at all. Fuses all check out, too.
Any idea what I'm missing? Could I be batting 0 with used parts and everything I'm installing is broken? Seem like long odds for that.

Any help is appreciated!

Thanks,

Brian

 

I'm not following - you get 12 volts everywhere on the harness, but no voltage to the switch(es)? Seems like there's a disconnect (literally and figuratively) there somewhere.

 

Would you believe I am still working on this? Yes- every component of the door wiring harness shows 11-12V when I probe (and backprobe them). Sent the CEM to Xemodex, they transferred to a different used one and sent it back to me with the all clear, it still isn't working.

- Driver, LR and LR passenger door windows and locks don't work, and now the driver power seat doesn't work. This is nuts!

 

The DDM is on a "dead end leg" of the low speed can bus.

Do you have continuity in the can bus wires going from connector 64/41 to terminals a:3 and a:12 on the DDM?

 

Hey Hoonk- thanks for the info. So I'm a novice with auto electrics, but let me tell you what I just found:

1. I used my multimeter to test the A3 and A12 connections. For the harness at the door (64/41), I backprobed using paper clips, then attached the multimeter leads to the paper clips.

2. A3 showed a value of 0 for continuity. My understanding is that's good. A12, the blue and red wire, showed 1. I believe that means a lack of continuity.

I am re-testing in a bit to see if I can duplicate. All testing was done with ignition off. If I repeat the tests and get a 1 at A12 again, does that indicate that wire has a break/short somewhere and I should trace it?

Appreciate the help!

Brian

 

When you test for continuity - you should unplug the DDM and connector 64/41 so there is no chance of any current in the wires.

No resistance (a complete circuit/wire) is 0 Ohms. That's what you have with the leads touching each other. A broken wire will have infinite resistance - it's an open circuit. (that's what the ohmmeter reads when it's turned on and the leads are not touching anything)



Google "can bus" for an explanation of how signals are sent across those two wires -

 

So my first step was to test between the door side wiring harness and the DDM. That checked out fine.

Then, I plugged the door side harness into the a pillar harness and that is where I am seeing the continuity issue. I was thinking that could indicate something amiss with that wire somewhere inside the a pillar. Am I not thinking about this correctly? Thanks.

 

So I found these broken wires in the harness in front of the drivers' seat. I'm curious- from the connector, it is one wire. However, it looks like they were connected to three smaller gauge wires. Do I braid those three smaller wires together and then connect them to the single larger wire that goes to the door connector? I am attaching an pic- shows one blue/red going into three blue/reds at the break. Thanks!

 

Yes all the same color wires are connected together. That is a can bus wire. The wiring diagram show that as junction 63/221.

 

I am way late in tying this one off- reconnecting the wires fixed the problem. VERY much appreciate all the help, @hoonk !