1996 850 Wagon Service Light On Topic is solved

PeteB · Post by **PeteB** » 10 Oct 2019, 09:08

Obviously an amp-clamp is the way to measure the wires individually, wonder if the
parts stores have them to loan.

PeteB · Post by **PeteB** » 11 Oct 2019, 17:16

I probably should have started a new thread about the battery dying overnight.

After sleeping on it, I'm guessing that an always hot wire is pinched before the
fuse since pulling fuses didn't cure the high draw. Perhaps it has something to
do with the smashed door - we should replace it ASAP.

Post by **abscate** » 12 Oct 2019, 05:45

Quick check, undo door harness and see if draw drops

PeteB · Post by **PeteB** » 14 Oct 2019, 05:47

It would be great to have a wiring diagram that highlights all the always on wiring for just
this sort of problem.

PeteB · Post by **PeteB** » 30 Oct 2019, 20:38

OK, got an amp clamp on sale from Sears and checked it out today.
The large bundle of smaller wires at the positive batter post does have one yellow
wire, I previously thought they were all red. The yellow wire has the high draw.
Anyone know what this wire is?
I might just snip it and see what is not working in the car, then solder it back.

I went through all the pages in the wiring diagrams that I could find and did not
find any yellow wire coming off the battery positive. I think that the diagram was
from 1995, not sure.

I had one more thought to pull the engine ECU or any module that plugs in before I
cut the wire.

PeteB · Post by **PeteB** » 30 Oct 2019, 20:46

I googled "yellow wire at battery post Volvo 850" and found this thread with another
person having the same problem. They snipped the wire and the car works fine, LOL!
But I'm sure that something is not going to work:
https://volvoforums.com/forum/volvo-850 ... nal-84878/

This is their picture but here is the yellow wire:

: VOLVO-850-YELLOW-WIRE.jpg (137.04 KiB) Viewed 671 times

Post by **abscate** » 30 Oct 2019, 22:09

That’s aftermarket stuff. Wiring diagrams aren’t going to help there

PeteB · Post by **PeteB** » 31 Oct 2019, 07:53

I don't think so, all those reds and the yellow normally go into a big lug that certainly
looks to be factory. In that picture the guy cut out the big factory lug in order to find
the leakage current, then put new lugs on the wires.
That car and our car both have the yellow wire that goes into the factory harness so
I'm quite sure that it is factory.

Post by **ZionXIX** » 31 Oct 2019, 09:53

Assuming you have time, you could follow it and solve the mystery!

PeteB · Post by **PeteB** » 01 Nov 2019, 03:22

I'm able to follow it about one foot then it enters a large harness.

1996 850 Wagon Service Light On Topic is solved

Re: 1996 850 Wagon Service Light On