1998 XC Electrical Problem

LakeFlambeau · Post by **LakeFlambeau** » 18 Jun 2012, 20:02

I purchased this car with about 135K on it back in March.
Car has been a pretty good runner. Check Engine light went on.
Overall the car still runs well.
Took it to my mechanic and found out Check Engine is coming on due
to fuse 11B/5 blowing.
There are a lot of items on this fuse.
The fuse blow right away when turning the key.

Items listed are as follows in the wiring diagram I found on this site.
Air Conditioning (A/C Relay), Heated Oxygen Sensor (HO2S) front, Heated
Oxygen Sensor Back, Canistor Purge (CP) Valve, Soleniod valve pulsed secondary
air injection system (PAIR), Evap canister shut off valve, Pulsed secondary air
injection system(PAIR) Pump relay, Turbocharger (TC) control valve, PTC
resistor air preheating

So there is a ton of stuff on this fuse.
My mechanic is not having much luck narrowing down what is blowing the fuse.
ANY ideas or help would be greatly appreciated. I can probably drive the car,
but it is getting hot and the AC will not work with this fuse out.
FYI, removed the AC relay and the fuse still blows.

Post by **BEJinFbk** » 18 Jun 2012, 20:41

There are a lot of mechanics in the world that don't like electrical problems.
In this case, you might suggest unplugging all the things on the list and checking
each one individually. One step at a time will find your problem. Be logical.

It may be something as simple as an O2 sensor wire melted to the exhaust,
but isolating all of the things that depend on 11B-5 is a good first step.

LakeFlambeau · Post by **LakeFlambeau** » 18 Jun 2012, 21:01

Thanks much for the response. I believe this is the case with my mechanic on this. I have
been thinking of suggesting this, but have refrained so far.
Hoping that someone here might have seen this before, and might have one
of those "easy fix or this is the most likely "
I have a backround in electronics, but with out a hoist and knowledge of
where all of these parts are exactly, I do not think I can attempt myself.
Agree that if you could unplug all items, and there a lot of them, and
end up with no blown fuses. Then plug each item in until you find the one
that blows the fuse.
Any additional suggestions ideas are greatly appreciated.....

Thorsteenster · Post by **Thorsteenster** » 12 Oct 2013, 12:24

Any updates on this?
I now am trying to track down a fuse blower for 11B/5, and I do believe I have everything disconnected and am now looking for a short.

LakeFlambeau · Post by **LakeFlambeau** » 12 Oct 2013, 15:04

What ended up happening is, my mechanic ended up getting frustrated with the problem.
He ended up putting a hunk of wire in the fuse location, and waited for something to start smoking.
He noticed a specific part, that I believe was some kind of a relay involved in emmisions equipment.
Sorry, I do not know what the exact part was. He replaced this part, and I have not had a spec of problems since.
So, this is a dangerous way to find the problem, but it worked for him.
I could try and find out the exact part, if needed, next week.

Let me know...

Post by **BEJinFbk** » 12 Oct 2013, 18:52

The method you've described could have melted your wiring harness irreparably,
killed electronic components or even set your car ( and this lunatics shop ) on fire...

NEVER replace a fuse with a higher rated fuse, and sure as hell NOT a "hunk of wire" !!!

I would heartily recommend another mechanic for electrical issues! This guy is
seriously dangerous. I hope he's better with the mechanical side of things.
Glad to hear that you've still got a car, but Dude....

LakeFlambeau · Post by **LakeFlambeau** » 13 Oct 2013, 07:00

Understand that it was dangerous, and I stated that. Just passing on how he located the shorted part that was blowing the fuse. NOT recommended way of troubleshooting Good luck locating your problem part