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melted Alt-to-engine ground. Why?

  • Thread starter Thread starter BornInAFord
  • Start date Start date Apr 25, 2005
B

BornInAFord

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Apr 22, 2005
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Bend, OR 97701
Apr 25, 2005
#1
  • Apr 25, 2005
  • #1
I fried the plastic on the alternator-to-engine-block ground while turning over a new engine. What would cause this heat? Is it a sign the alternator is toast?

It is a used stock multi-wire alternator from the old engine with new wiring on my 1966. It worked well before putting on the new engine. The engine is a 302 with Pertronix II dizzy and late model high torque mini-starter.
Thanks,
Daniel
 
C

C0V3R

Member
Feb 14, 2003
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Australia
Apr 25, 2005
#2
  • Apr 25, 2005
  • #2
Probably a loose connection causing arcing. Otherwise a bad ground connection from the engine to the battery resulting in the current going through the alternator ground. Check your main ground strap.
 
B

BornInAFord

Member
Apr 22, 2005
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Apr 25, 2005
#3
  • Apr 25, 2005
  • #3
C0V3R said:
Probably a loose connection causing arcing. Otherwise a bad ground connection from the engine to the battery resulting in the current going through the alternator ground. Check your main ground strap.
Click to expand...
You got it! A poor ground at the engine block bolt sent all the current back up through the alternator housing. A 12 gauge wire was never designed to take that kind of current.
Thanks,
Daniel
 
C

C0V3R

Member
Feb 14, 2003
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Apr 26, 2005
#4
  • Apr 26, 2005
  • #4
Good to know it helped! How did the engine startup go?
 
B

BornInAFord

Member
Apr 22, 2005
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Bend, OR 97701
Apr 26, 2005
#5
  • Apr 26, 2005
  • #5
C0V3R said:
Good to know it helped! How did the engine startup go?
Click to expand...
It hasn't started yet, and I'm waiting on another set of alternator wires to come from NPD. With the melted wire jacket it also melted other wire coverings and I was not wanting to just tape it and go. I've waited this long... might as well wait another day or two.
Daniel
 
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