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So I set one of my wires on fire... by Threedog
Started on: 05-09-2015 07:21 PM
Replies: 9 (239 views)
Last post by: cvxjet on 05-10-2015 10:57 PM
Threedog
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Report this Post05-09-2015 07:21 PM Click Here to See the Profile for ThreedogClick Here to Email ThreedogSend a Private Message to ThreedogEdit/Delete MessageReply w/QuoteDirect Link to This Post
So I relocated my battery to the front(yay!) this week and almost set my car on fire(boo..). Car is a 3800 swap in the build process, computer was NOT plugged in during the incident.

Initially I had my battery wired up with 2ga POS running to the starter and splitting to the c500 connector post(battery terminal), with a 2ga NEG grounded to the front chassis. It wasnt cranking so I got 4ga NEG wire to run all to the block and rear chassis for a better ground.

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I ended up grounding the NEG to the bolt above the starter and the engine cradle. I cleaned both of these off to insure the connection.
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The second I plugged the NEG cable in I saw smoke coming from the area around the C500 connect, fearing the worst I went back and looked to find that the the thick, red, alternator charge cable(from the alt peg to the battery terminal under the c500) had burned straight through. And the second my NEG is hooked up to the batt, it trips the battery fuse.

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What did I do wrong?
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Gall757
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Report this Post05-09-2015 10:15 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hard to follow what you have done.

The safer way to do this is to leave the frame out of the circuit, and run a negative cable back to the original connection on the engine block.
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IanT720
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Report this Post05-09-2015 10:26 PM Click Here to See the Profile for IanT720Click Here to Email IanT720Send a Private Message to IanT720Edit/Delete MessageReply w/QuoteDirect Link to This Post
Bingo^ I ran my 2ga ground all the way back the the head, then a short piece to the deck lid hinge. I still have some ground straps to add, but everything is perfect as is. Cranking was insanely fast, and my stereo plays beautifully. Make a better ground. You can do a lot of damage, Phonedawgz wrote a thing about people grounding only to the front and the scary things that could happen if that ground fails or isn't as good... Fire being #1.
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olejoedad
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Report this Post05-10-2015 06:40 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would check for a bad alternator, probably shorted internally since the ALT charge wire burned up.

What is the black (blue?) wire that appears to be coming off of the battery wire in the first picture?

[This message has been edited by olejoedad (edited 05-10-2015).]

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Threedog
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Report this Post05-10-2015 01:26 PM Click Here to See the Profile for ThreedogClick Here to Email ThreedogSend a Private Message to ThreedogEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

Hard to follow what you have done.

The safer way to do this is to leave the frame out of the circuit, and run a negative cable back to the original connection on the engine block.


It is a 3800 so I am not sure where the "original" connection is, Ill find out though. Splitting between that and the deck lid connection seems like a good idea though?

 
quote
Originally posted by olejoedad:

I would check for a bad alternator, probably shorted internally since the ALT charge wire burned up.

What is the black (blue?) wire that appears to be coming off of the battery wire in the first picture?



It never even got to cranking, so the alternator did literally nothing. I noted that the alt wire was touching the alternator case due to a rubber part breaking and falling off which could have caused the short(making it act as a ground). Also the blue wire is a trick of the camera, it is a cut wire happened to end right at the other wire making it look like they joined(its a 3800 swap).
None of this explains why after the short, when I reconnected the battery and put it in accessory mode I got power but it tripped the battery fuse..

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Gall757
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Report this Post05-10-2015 01:59 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Yes...a hot wire touching the alternator case is a dead short....car running or not.

What is a battery fuse?...is it the fuse that says BAT?

[This message has been edited by Gall757 (edited 05-10-2015).]

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phonedawgz
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Report this Post05-10-2015 03:47 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
cig lighter wire touching ground? Coins in the cig lighter?

[This message has been edited by phonedawgz (edited 05-10-2015).]

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Threedog
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Report this Post05-10-2015 03:48 PM Click Here to See the Profile for ThreedogClick Here to Email ThreedogSend a Private Message to ThreedogEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

Yes...a hot wire touching the alternator case is a dead short....car running or not.

What is a battery fuse?...is it the fuse that says BAT?



The fuse trips even without the wire hooked up though(it burned through.

Yeah the 10AMP BAT fuse.

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Gall757
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Report this Post05-10-2015 03:52 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
The BAT fuse is connected to a bunch of different things, but the first place to look is the cigar lighter next to the ALDL. it often shorts.

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cvxjet
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Report this Post05-10-2015 10:57 PM Click Here to See the Profile for cvxjetClick Here to Email cvxjetSend a Private Message to cvxjetEdit/Delete MessageReply w/QuoteDirect Link to This Post
I did not like the idea of a large (0 gauge) wire running hot along the gas tank- I installed a Ford style solenoid up front(And a Battery switch) and have an 8 gauge wire running power back to the battery post terminal while the 0 gauge wire hits the starter- it's only juiced when starting. I also ran the ground back to the block- Ran both thru the gray plastic electrical conduit; cut it to the right length and then bent both ends up(with a heat gun) so that the wires are well protected. I ran the positve 8 gauge wire in the conduit with the ground 0 gauge so that if I somehow damage the bottom of the car, it will short out to the ground wire, popping the fuse I installed, before shorting to the gas tank.....Sounds good in theory, at least.....(I have a mental image of Colonel Blake in MASH when someone blew up the latrine with him in it- ".....BOOM......")
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