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> unpleasant surprise, new fuse panel install
r3dplanet
post May 26 2012, 08:58 PM
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Quite a while back I bought an Engman fuse panel. It's lovely and I'm happy that I bought it. I finally installed it today and, after a little smoke, made an unpleasant discovery.

It turns out that the metal bracket on the back of the fuse panel touches right up to a positive wire connector that has live voltage.

Hence the smoke.

My question is why is this battery connector sitting right here so close to the panel? With the new fuse panel bolted up it makes direct contact between the rear metal bracket and the live connector making a really solid short circuit. Has anyone else noticed this? I have no idea if my connector is even in the stock location. There doesn't seem to be another convenient spot to relocate it to.

Thanks,
Marcus
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Mike Bellis
post May 26 2012, 09:12 PM
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You have an early car. You could remove the connection from the bracket. Bolt and shrink tube the electrical connection. Then tie it to the harness.
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r3dplanet
post May 26 2012, 09:18 PM
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Entirely true. Mostly. The car is a 1971. The engine and rear half of all the wiring is from 1973. If it just needs to connect, then I'll find a fancy connector and move it out of the way.

Thanks.


QUOTE(kg6dxn @ May 26 2012, 08:12 PM) *

You have an early car. You could remove the connection from the bracket. Bolt and shrink tube the electrical connection. Then tie it to the harness.

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Mike Bellis
post May 26 2012, 09:23 PM
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Later cars ~'72ish had two wires from the battery directly to the fuse panel and ignition switch. Yours has one big wire split under the dash. I assume Porsche changed it due to arcing under the dash.
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914Bryan
post May 27 2012, 09:17 AM
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On my 74, that is where the ground wires bolt to.
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914itis
post May 27 2012, 09:43 AM
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I had my share last year on my 70, check this thread . http://www.914world.com/bbs2/index.php?sho...=115319&hl=
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914itis
post May 27 2012, 10:43 AM
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In my case, the bolt touched that the block where the main red wire from the battery is attached. My red wire and other wires were melted. I had to pull the harness from the tunel, inspect, tape and replace as necessary.

you may want to do the same.

I added a fuse on the engine bay on that red wire for prevention.

Good luck!
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Tom
post May 27 2012, 12:31 PM
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This is the reason I put together a fuse block kit for fusing the red wires from the battery. I have a test in the works to make sure the 4 way fuse block will handle the necessary current thru a single fuse connection for the early cars with only three red wires at the battery positive. I will post results when I have the test up and finished.
Tom
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jimkelly
post Oct 16 2013, 02:05 PM
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I just had the same problem as OP - but manageable (IMG:style_emoticons/default/sad.gif)


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Tom
post Oct 16 2013, 06:17 PM
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A word of experienced advise for those who do their own electrical work. It is standard practice to disconnect the battery while doing electrical work. When you are finished, hook up the battery SLOWLY. If there is a large spark, don't keep it connected, find out why the spark, then re hook up the battery. Better yet, devise a fuse block assembly to fuse those large red wires going to the dash and relay panel.
Tom
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r3dplanet
post Oct 16 2013, 07:44 PM
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I'm surprised no one stomped on the "disconnect the battery" advice sooner. In self defense, I always disconnect the battery. When my meltdown happened it went really fast and the damage was minimal, so I knew enough about that. I couldn't imaging doing a job like this without disconnecting the battery. I think the real issue is just that the positive wiring connector is completely unseen when changing the fuse panel. It wasn't until I removed everything and really stuck my face under the dash and moved a fistful of wires before I realized that there WAS a central hot connector located right next to the corner of the fuse panel. Obvious in retrospect, but not at all obvious at the time of installation. Hence my post.
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jimkelly
post Oct 16 2013, 08:05 PM
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I actually installed the fuise box months ago without a battery in the car. today I was hooking up a parking light when things went bad. still I should have disconnected battery.

question is how best to butt these 4 wires together? the fattest one must be 8 awg or fatter?


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914itis
post Oct 16 2013, 08:14 PM
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I will post a picture of my distribution box that can be purchased at a radio / alarm installation place
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914itis
post Oct 16 2013, 08:17 PM
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I used something like this and a fuse between the block and the battery. I believe the fuse is 50 Amps.


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mikesmith
post Oct 16 2013, 09:40 PM
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QUOTE(914itis @ Oct 16 2013, 07:17 PM) *

I used something like this and a fuse between the block and the battery. I believe the fuse is 50 Amps.


I'm a fan of these Bussman fused / switched power distribution blocks. You can get them from various sources; Waytek for one:

http://www.waytekwire.com/item/46095/POWER...Y-MODULE-STUDS/

The long J-case fuses are available up to 60A. If you'd rather not pick out the individual components, you can get a kit from this guy with boots and the relay connector pieces:

http://www.concept-customs.com/Electrical/Electrical%202.htm

Or if you just want a fuse block:

http://www.waytekwire.com/item/46089/FUSE-HOLDER-FOR-MINI/

If you're feeling super-cheap, BMWs from at least the E30 onwards have a 250A maxi fuse in a box hung off the B+ terminal on the battery, or in some cases near the jumper cable connection under the hood. You can get these cheap from your local wrecker. Blowing a 250 maxi fuse takes some doing; you are typically going to be better served with a few separate circuits and smaller fuses.

Don't use anything from the "car audio stylez" department. If it's polished, translucent, gold plated or has LEDs on it, stay away; a) it's crap, and b) it's not designed for life in a harsh environment.

= Mike
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mikesmith
post Oct 16 2013, 10:01 PM
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QUOTE(jimkelly @ Oct 16 2013, 07:05 PM) *

question is how best to butt these 4 wires together? the fattest one must be 8 awg or fatter?


If you're just doing this once off, and this is inside the cabin, there are so many options it will make your head spin.

The simplest and cheapest is to pull the four together in the same direction, find some thin copper wire (solid core telephone wire would do the trick), bind the four butts together by wrapping 4-5 turns of the solid wire around them and solder it into a blob. Wrap with electrical tape (not recommended) or adhesive-filled heatshrink (better). Use a ziptie 1" or so away from the bare wire to keep it all together while soldering, or you'll burn your fingers before it takes properly.

There are any number of screw or cage terminal distribution blocks that you can use. The Wago 26x family (plus insulated jumpers) work well, but you don't want to be ordering a tiny number of them. I got my last batch from a junk bin at Halted.

You could go completely overboard with something like this MetriPack 280-based system:

http://www.waytekwire.com/products/21/Splice-Pack-System/

TBH, I don't see anything fundamentally wrong with the stud terminal in the earlier pictures in the thread, other than it's in a bad place. Move it somewhere else, or get a replacement like:

http://www.waytekwire.com/item/47213/JUNCT...CK-87-STUD-RED/

Crimp some O-ring terminals onto your wires and feed them through a boot so that the bolt is covered and you're in business...

= Mike
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Tom
post Oct 17 2013, 04:35 AM
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Well, my intent wasn't to stomp. Merely to give the community a very valid reason for disconnecting the battery. If everything is off when reconnecting the battery, and you get a spark upon initial contact of the battery connector to the post, stop and check your work because something is not right. On our cars there is very little to no current flow with everything off, exceptions being the clock or newer radios/stereos and there should be very to no spark when hooking up the battery. If there is a bigger spark and you have been doing electrical work, something you were doing is causing a problem and you can contain the damage by following this simple step.
Tom
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JWest
post Oct 17 2013, 06:27 AM
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This thread was brought to my atttention suggesting that I should be concerned about this.

However, the issues above did not occur with a JWest fuse panel. Our fuse panal does not use a metal strap above for this very reason.

We use a nylon spacer to mount the fuse box so even if the screw near the power block touches solid, it is isolated and will not cause a short.

The first step in our instructions that involve touching the car is to disconnect the battery cable, which should be done before any electrical work.
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chads74
post Oct 17 2013, 07:35 AM
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QUOTE(914itis @ Oct 16 2013, 07:17 PM) *

I used something like this and a fuse between the block and the battery. I believe the fuse is 50 Amps.



I have been looking for something like this. Where did you get yours?
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JeffBowlsby
post Oct 17 2013, 09:32 AM
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With due respect to the 'inventors' of these aftermarket fusepanels, I am not convinced these are worth the trouble over the factory stock fusepanel. I think they are solutions to a non-problem and in fact create other problems just to make them work, and the experiences in this thread prove that. They are just adaptations of inexpensive generic fuse boxes interposed into the factory wiring for minimal if any benefit. Why anyone would give up the quality built factory fusepanel is a mystery to me. Just because these are new, does not mean they are better. Some seem to be better than others, in fairness. I would really like to see a 'shoot-out' comparison to better understand their characteristics compared to each other and with the stock fusepanel by a neutral person that can give us the facts.

My concerns are:

1. Sure they use new improved fuses - so what, the original bullet fuses work fine.

2. Some complain that they knock the fuse cover and fuses off getting in/out of the car. That has never happened to me in 35 years of driving these cars. Just be cautious or zip tie the cover on if this is problem for you.

3. The shorts to ground and melted wires for the early cars described above are serious hazards - why should the factory terminal block need to be relocated, wrapped, taped to the harness or left to hang free just to accommodate the new fusepanel? Its stupid to have to do this and should not need to be done - it screams to me that these fusepanels create more problems than they solve.

4. The wires from the harness do not connect onto the fusepanel well because they attach through the sides of the fusepanels, putting strain at the wire-to-wire terminal junction. So as a result, the harness wrapping needs to be cut and loosened up to minimize this strain. Another thing that is contrived.

5. The factory fusepanel has busses for some of the circuits that the aftermarket fusepanels do not have becasue they are generic adaptions. How are these circuits handled with the aftermarket fusepanels and has the engineering been done to assure that these affected circuits are not under/overloaded? Are adapter tabs used? If so..another contrivance.

There may be more, but thats it for now.
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