2006 Ouback keeps blowing 20 AMP back up Fuse under the hood

[3Pin]

I just bought this and the radio,info display with outside temp, and all interior lights were not working.   Read up on it and it said, replace the 20 amp under the hood #2 Back Up fuse.  I can't even get a fuse in there and it will arc sparks and blow before it is fully inserted into the fuse block.   The car has stock everything and it appears to be a bad ground somewhere.  Anybody else have this happen to them?

 

[Numbchux]

Back up lights are in the hatch, right?

 

These are notorious for having damaged wiring between the body and the rear gate. The dealership where I worked stocked rear gate harnesses (MSRP was about $85, I think there are 3 different part numbers, use your VIN to look up). Obviously individual wires can be repaired, but this will not be the first time you have it happen.

[3Pin]

It is all of the cabin lights in the entire car, stereo and clock/outside temp display.   So you think there is a good chance one of the wires from the body to the tailgate are shorted then?  The back up fuse is not really related to back up lights from what i can tell.  The fuse that keeps blowing is the #2 fuse under the hood that controls all of the things I have mentioned.  The horn and air bag light are on also.  I wonder if that is related or a bad clock spring perhaps?

 

Edited December 20, 2020 by 3Pin
clarification

[lmdew]

If you can unplug that harness and then see if the short is gone.  Nice.

[3Pin]

I just peeled back the rubber boot covers that hold the wires from the rear tailgate to the chassis and the wiring looks clean and connected.  no breaks I could see.  Will check closer in the AM.

[brus brother]

There is an image within this linked thread of the wires I found broken inside the rubber boot on the passenger side of my 05 OB. I did the repair without digging in to find the connector for the harness. Initially, I didn't "see" the break but after tugging on each wire, it became obvious.

That being said, if you can locate the harness upstream and disconnect, that is a more definitive diagnosis. You may ALSO have some crappy wire within the boot and tugging on wires may cause an additional problem that will confuse the issue if your initial gremlin lurks elsewhere.

Edited December 21, 2020 by brus brother

[idosubaru]

Is there any custom or added on electrical device?  If there is that item likely has a problem.

Then do what lmdew said.  Look up everything that fuse feeds - unplug each device one at a time and see which one causes the fuse to blow. Unplug clock spring, insert fuse. Unplug stereo - insert fuse.

[idosubaru]

I don’t see where this is a rear hatch fuse.  

I’ve had no problem repairing them.  splice/solder them well with high quality wire and splices and enough extra slack to get it as close to stock routing as possible and push the excess back into the body cavity.

test them all with a voltmeter.  The metal can break before the insulation/sheathing.  On some, Ive traced all the wires with a volt meter, and found 2 completely broken and one intact wire that was broken inside the sheathing.  It tested bad and when I trimmed back the insulation the copper wire was broken inside.

I think if you pull hard enough the sheathing stretches and breaks but an intact wire won’t. I think I’ve done that before as well.  But you don’t want to pull it out of a connector so you have to be careful how you pull and this will only work  in situations where you have enough access to make sure you can pull it without damaging anything. Need to be able to grab both sides or ensure it’s secured tightly  

repeat failures are a poor job or someone missing one of these internal breaks. 

or just repair them all!  I’ve never done that.

pulling and installing the harness to install a new one is a terrible job.  I’ve done it twice and will avoid it every day of the week over splicing a few simple wires. 

[lmdew]

On my 2000 Impreza OBS the connector was on the passenger side under the plastic trim down by the taillight.  

[heartless]

just repaired the wires going to the hatch on the other half's 06 Outback about a month or so ago.. on close inspection, out of all of them (14), there were only a couple that were not showing signs of fatigue.. just fixed them all to be done with it.

Was a heck of a job, getting the interior bits out just to get good access to the stuff.

my personal preference is not to solder the joints in vehicles - but a good western union splice with heat shrink over it. soldering can cause further issues down down the road from vibrations.. but to each their own.

[brus brother]

step 1 : to gain access to make splices,  first I rolled back the boot to locate breaks then I tied a piece of dental floss (I'm a retired dentist ;-)) to one of the loose ends and pulled it back out, spliced enough wire to make it work and then pulled the extended piece back through to reconnect to the other end of the broken wire.

step 2 : discard floss

Edited December 21, 2020 by brus brother

[Numbchux]

For the record, I took "back up" to mean reverse. But this is a much larger circuit, providing constant power to many circuits, and I don't think any of them are in the rear hatch.

[3Pin]

found broken wires passenger side from tailgate to hatch.  3 or 4 at least.  Will pull it inside  the garage to work on the splice.

[brus brother]

" I can't even get a fuse in there and it will arc sparks and blow before it is fully inserted into the fuse block."

Hate to waste another fuse but curious if you just separated the broken wires from each other you could diagnose this as the trouble area.

[3Pin]

That is a good thought.  I think I will put some electrical tape on the wires that don't have insulation on them any longer and see if that stops the fuse pop before the final repair. Some are still connected but have no insulation, others appear to be severed.