Reversing Lights And Rear Camera Power Problem

[NickPr]

I've been trying to fix this myself / with our converter, but could do with some advice, please. I'm stuck!
T6 LWB 4motion 18' plate DSG. Rear camera, rear parking sensors.

I've also read this thread, though my problem is different. My fuse is not blowing.
Rear Camera Oem Cable Routing

Problem: no reversing lights or rear camera after van converted. Rear parking sensors work. Fuse SC18 is not blown. I know SC18 gives power to the camera and reversing lights. I've seen the wiring diagram posted on the thread above, but don't really understand these drawings.

1st repair attempt: the converter took it in, ran a new 12v cable from the orange connector under the seat to the rear harness, and this seemed to solve the problem .... just long enough for me to drive home. I'd checked before I left the converter, then once I was home, no reversing lights and no rear camera! It's not intermittent; it just doesn't work. I can take it back to them (and I will do), but would rather see if anyone here can help me solve the problem first. It'd be good to understand what the issue is.

Details of that first repair: they ran a new 12v cable from under passenger seat, up along the roof and spliced it into the green/black cable that runs across the back roof. They cut off the original green/black line coming from the left. So the new cable joins into the green/black wire to the right of where they cut it. (see pictures attached). This makes sense; they thought maybe the 12v reversing/camera wire was damage in the roof line. This seemed to fix it initially but the fix has failed for some reason; whatever is going wrong, obviously went wrong again soon after they got it working again. Again, SC18 fuse has not blown. I've checked their splices and they look good. (their new wire is green/white in the pictures attached).

Looking at what they have done, they have also run a wire from this same splice point down to the left rear quarter and spliced it into the wires running into the left rear light cluster. I can't quite understand why this is necessary if they were successfully bypassing a damaged roof cable with their new wire. ?

Testing:

• I haven't been able to test if there is 12v when in reverse in their new wire (new green/white spliced into green/black original)
• The video cable and connector looks fine (and this wouldn't explain the loss of reversing lights).
• On the little 3 pin connector running parallel to this (white wires on left side, coloured wires on the right side) Not sure what this connector is, but I think it is camera power etc? :
  • I am detecting 12v on the blue/red line when in reverse and also when not in reverse.
  • zero volts on the other pins when in reverse or not.
  • Is the green/black wire going into this connector the same as the green/black wire in the group of wires running parallel to this connect? If so, this is the wire my converter has spliced their new green/white 'bypass' cable into. I'm not measuring 12v at all on this green/black line at the connector in the middle of the rear roof - see pictures.

I just can't figure out what the problem is. If a damaged wire really was the issue, surely fuse SC18 would have blown originally or would have blown this time after their repair failed?

I just can't understand why I seem to have a power issue (indicated by loss of camera AND reversing lights) but no fuse problem and new 12v line made it work, then it stopped again.

Any thoughts or ideas gratefully received.

 

[DaveyB]

That is strange as the wiring looms for these two circuits aren’t fed along the same sides of the van as you will have found out. The camera runs up the offside b-pillar from under the drivers seat and then along the roof line, reversing lights pass along the nearside. When I started reading I thought you’d suffered what I had, which was an incompetent company damaging your wiring loom; but considering how the circuits work briefly with all the things that have been tried (secondary power supply loom etc) it can’t be that. Equally with SC18 intact, also tends to rule that one out.
For the camera side of things have you tried doing a hard reset on your head unit (if you have OEM unit press and hold the power button for about 10 seconds).
Very weird though. Sorry can’t be of any more help. If you’d have needed to know how to strip the camera loom out, i’d have been able to assist in that, as this is what mine looked like in doing so to fix the F-up of someone else.

Best of luck getting it sorted. If you trust the converter then give it them back and tell them to sort it.

 

[NickPr]

Cheers. It is an odd fault. Sadly beyond me I think, so back to the converters. I suppose it could even be a warranty issue, but I can't see VW accepting that now it's been converted. Back to the converter it is. Promising they got it working once; but since it has failed it doesn't move us any further forward.

I guess that explains why they have spliced the new wire into 2 places? One to hit the camera line, and one to hit the reversing lights line, even though they originate from the same fuse?

PS; soft reset done; no change. I suppose it could be that a hard reset made it work, then it failed again? Can't see that converter would have disconnected battery when they put the new wire in though.

 

[chris cadiz]

Had the same issue as described above. Power/fuses all OK, but seemed a bit of a coincidence that the issue occurred after a pop top was fitted. Took it back to the converters who discovered that there is a plastic micro dot coax cable connector in the original vw harness across the back of the van which had popped open. The connector (grey and purple) wasn't damaged but didn't seam to click together. Problem solved by simply wrapping a bit of tape around the connector