Short to ground... where is it? Fuse 11A/8 Topic is solved

Post by **bmdubya1198** » 06 Jun 2019, 14:35

I've discovered that the problem that I've been chasing for months on my 2000 V70R is a short to ground on some power wire, but I don't know where. When I probe the 11A/8 fuse (in main fuse box, one of the larger fuses) against ground, it shows between 7-10 ohms if I have a door open. However, if I close all the doors, it climbs to open circuit.

I've already torn apart the whole harness between the main fuse box and the CEM/fuse box in the car, and the wire coming from that terminal is totally in tact. No wear that could be shorting it out. It seems that the wire is linked to something else within the CEM fuse box that's shorting to ground.

The interesting detail here is that the only time I'm seeing resistance to ground is when a door is open. For some reason I can't find a diagram for the door latches, but I'll continue looking. In the meantime, does anyone know what could be shorting out when a door latch goes into the open position?

Post by **abscate** » 06 Jun 2019, 14:40

The trigger wire for the door lights and lock module

Normally open, go to ground when door opens

Post by **bmdubya1198** » 06 Jun 2019, 15:03

That's probably it... now to find where that runs. Thanks!

Post by **wizechatmgr** » 09 Jun 2019, 23:03

bmdubya1198 wrote: 06 Jun 2019, 15:03 That's probably it... now to find where that runs. Thanks!

Goes to every door and other locations... Odds are the short is in a door...

Post by **bmdubya1198** » 10 Jun 2019, 15:59

So I checked my cousin's '99, and that's normal behavior. Turns out EVERYTHING I "found" is normal behavior. So I've hit yet another dead end.

The problem: ECM-6B00 and ECM--6300 (both intermittent short to ground/signal too low codes for the ETS light and CEL) will not go away. It seems I have about 30 ohms to ground on those wire in key position 2, so that could be the short. The questions here are 1- is that normal, and 2- if not, what could be the problem? I'm pretty sure this isn't a wiring issue, and the cluster is not the problem (swapped it, no difference). Is the ignition switch a possibility?

Post by **bmdubya1198** » 08 Aug 2019, 16:28

I can consider this particular issue solved, I think. I replaced the B+ fuse box cable and scanned multiple times with VIDA, and the codes did not come back. Now only one code for the clutch sensor (which is because I haven't installed it).

Don't know why I didn't do this sooner!

Post by **abscate** » 09 Aug 2019, 03:53

Did that cures your ECM codes or just the door short problem?

Post by **bmdubya1198** » 09 Aug 2019, 07:11

Just the ECM codes, I haven't figured out the door short issue. From what I can find, it seems that's normal activity for that circuit.

But who knows... is it normal to hear the lock motor sound when I shut the driver door? That's just something this car has always done and I found it a little weird... just thinking maybe it has to do with that possible short.

Post by **scot850** » 09 Aug 2019, 19:45

The wiring harnesses are prone to cracking where the harness enters the door. Could be you have a wire that is shorting in there. I have had to repair 2 or 3 of these.

Neil.

Post by **abscate** » 10 Aug 2019, 03:35

bmdubya1198 wrote: 09 Aug 2019, 07:11 Just the ECM codes, I haven't figured out the door short issue. From what I can find, it seems that's normal activity for that circuit.

But who knows... is it normal to hear the lock motor sound when I shut the driver door? That's just something this car has always done and I found it a little weird... just thinking maybe it has to do with that possible short.

I think that’s the mode where the car tries To lock doors but sees one of them I see open.

It does point to a wiring fault somewhere, but not necessarily in the door moving