Melted Fuse - with pics.

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jordan_ellipsis
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Post Thu Dec 06, 2012 9:58 am

Hi guys

Car model: 1991 318i

At some point in my car's history a wrong value of fuse was fitted at 21 (various interior lights, clock, radio memory, on-board computer)

A fault with the boot light caused it's wire to be burned, which stripped it back halfway down the loom. Very lucky not to have caused more damage. I have since removed the wire completely and thoroughly checked for further damage.

The fuse in slot 21 was completely melted as a result.

I've tried scraping out as much of the melted plastic as possible while trying not to harm the connectors underneath (see pics)


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The car still drives and the only notable drawback is the CD player not working. (the interior lights never really worked)

I think my options are to:

-repair the slot by getting the rest of the fuse out and replacing the connector (as done in this thread [url]http://www. ... c&t=175810)

-rewire to slot 25 (not in use)

-replace the whole fusebox (huge job, hopefully avoidable)


What would you recommend?

Really appreciate any help on this matter.

Best,

Jordan Craig
BMW e30 318i 1991 (white)
Green
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Post Thu Dec 06, 2012 12:36 pm

You could just replace the top half of the fuse box, bit of a pain pulling all the connectors out and putting them back in but it's done then. But it would be easier to just move the connection as you say to Fuse 25 if it's not in use.

Have you fixed the problem that caused this? 8O
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DanThe
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Post Thu Dec 06, 2012 12:53 pm

Id rewire it to a different/unused fuse slot. Changing the fusebox is a mission
Simon13
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Post Thu Dec 06, 2012 1:12 pm

there is 1 spot that is always unused on an e30. As dan says relocate. You'll cause more drama/troubles with any other route
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Post Thu Dec 06, 2012 2:04 pm

You can rewire the circuits to any slot you like. But theres something seriously wrong in one of the circuits connected to that fuse. And possibly a too higher rated fuse substituting what was supposed to be in the slot?

The clue is in you're post. Interior lights sketchy, CD player not working. Fuse 21 is a reletively low usage circuit. theres either something causing too much load for the circuit or theres a major short somewhere. That circuit is interior lights, radio, torch docking point, Clock etc.

Big HiFi possibly? Trapped a wire where trims been removed and replaced trapping a wire?

I'm no electrical expert but I would say you need to find the cause before burning out another slot.
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Brianmoooore
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Post Thu Dec 06, 2012 8:10 pm

Fuses 21 to 28 all connect to the same piece of copper on the circuit board on their side nearest the centre of the box, and all have wires connected to the outer connectors, so the way forward is to transfer the wire on 21 to either 25 or 26, clean up the carbon around the burnt fuse and FIND THE FAULT. Exposed wiring on the boot lid hinge and DIY radio installs are the favourites. Glove box light is another strong suspect on earlier cars, but shouldn't be on a '91.
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jordan_ellipsis
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Post Fri Dec 07, 2012 2:09 pm

Thanks for the input guys; i really appreciate it!

The fault was with the boot light. Someone had mucked around with it over the years, and had rewired it incorrectly. I stripped the circuit out the car completely so it won't be a problem anymore. Having a boot light is not on my priority list right now, but I'll get round to fixing it one day...

So it looks like relocating to fuse-slot 25 is the best option.

How easy is it to get underneath the fuse slots and do this? Looking forward to getting home and giving this a bash!

Cheers,

Jordan
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Post Fri Dec 07, 2012 3:45 pm

Very easy, just remove the screws in the fusebox and the top should pop off :)
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Brianmoooore
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Post Fri Dec 07, 2012 6:10 pm

Green wrote:Very easy, just remove the screws in the fusebox and the top should pop off :)
One outside and two inside. DON'T TOUCH the hex headed bolt!
You can pull quite hard on all the wires to get the top up far enough, without causing any damage. Make sure the 5 pin flat plug is pushed fully into place before you bolt the top down again.
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Post Sun Dec 09, 2012 4:11 pm

Brianmoooore wrote:
Green wrote:Very easy, just remove the screws in the fusebox and the top should pop off :)
One outside and two inside. DON'T TOUCH the hex headed bolt!
You can pull quite hard on all the wires to get the top up far enough, without causing any damage. Make sure the 5 pin flat plug is pushed fully into place before you bolt the top down again.
Ok i'm going to have to ask why not the hex bolt now?
2.8 development thread http://www.e30zone.net/modules.php?name ... c&t=170822

m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
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Brianmoooore
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Post Sun Dec 09, 2012 8:33 pm

HairyScreech wrote:
Ok i'm going to have to ask why not the hex bolt now?
Because it bolts the incoming cable from the battery to the circuit board. If you cause a poor connection here the fusebox will be totally scrap.
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jordan_ellipsis
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Post Tue Dec 18, 2012 1:39 pm

Sorry for the delayed reply.

I ended up fixing this with an in-line fuse! I'll get round to rewiring the slots when i get some time - possibly over Christmas! :cool:

Thanks very much for all the advice guys, it's appreciated.

Jordan