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  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

charging system problem

  • Thread starter Thread starter 6Stang7
  • Start date Start date Jan 7, 2006

6Stang7

New Member
Jun 1, 2003
1,470
0
0
Livermore, CA
Jan 7, 2006
#1
  • Jan 7, 2006
  • #1
so, i was driving back from the gf house one night and on my way home i noticed that all of my lights went dim a little bit. when i looked at the volt gauge i saw it was at 12V. ok, so the reg or alt went out i figured. when i was about a block or so home, i saw that the volt gauge jumped back to 14V+. so the next day when i start it, it's back at 12V. i when and looked around and saw that one of the wires that hooked up to that alt was frayed and hand about 2 copper wires holding it on. i figured this was what was wrong. i bought a new alt AND new wiring harness, put both on, and started the car up. still read 12V. so i put a new volt reg on (the new style, not the old mech. type) and it still read 12V. i did notice a small fuse on the fuse block that was burnt, but other then that i am totally lost on what could have happened. any ideas?
 

6Stang7

New Member
Jun 1, 2003
1,470
0
0
Livermore, CA
Jan 10, 2006
#2
  • Jan 10, 2006
  • #2
so no one knows? any know exactly how the charging system on a 67 works?
 

krash kendall

Active Member
Nov 19, 2004
1,258
0
36
Aldergrove, B.C. Canada
Jan 10, 2006
#3
  • Jan 10, 2006
  • #3
Measure the voltage at the battery. You should have 14.4 ish when running and 12.5 ish when car is off.
 

6Stang7

New Member
Jun 1, 2003
1,470
0
0
Livermore, CA
Jan 11, 2006
#4
  • Jan 11, 2006
  • #4
ya, i did that. like i said, my volt meter reads 12Vs running. i got a new alt, new alt wiring harness,and new volt reg and it still isn't working. i'm totally lost here. anyone?
 

2nd Mustang

Founding Member
Feb 24, 2002
2,488
0
46
Southern California
Jan 11, 2006
#5
  • Jan 11, 2006
  • #5
Try measuring voltage at output of the alternator, then work your way back to the battery. Put the ground (common) lead of the voltmeter at the negative post of the battery then move it to a ground source on the body to see if the voltage changes, which would mean a bad ground source or cable.

A lot of things could cause voltage drops, you just have to try and isolate possible causes, otherwise you could go nuts by just replacing everything.

Maybe a worn belt?
 

6Stang7

New Member
Jun 1, 2003
1,470
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0
Livermore, CA
Jan 12, 2006
#6
  • Jan 12, 2006
  • #6
nah, belt is less then a year old. anyone have a complete diagram of the alt system on a 67?
 

krash kendall

Active Member
Nov 19, 2004
1,258
0
36
Aldergrove, B.C. Canada
Jan 12, 2006
#7
  • Jan 12, 2006
  • #7
http://www.hammar.dyndns.org/~djhamma/wiring/wiring1967.htm
 
M

mustangman1974

Member
Jan 17, 2004
463
0
16
Jan 14, 2006
#8
  • Jan 14, 2006
  • #8
if a fuse was burnt and you have 12 volst runnign on a new system you have a short. One of thiose shorts thats gona Pi$$ you off finding it too.
 

jdowen2

New Member
Dec 18, 2005
48
0
0
Mesa, Az
Jan 14, 2006
#9
  • Jan 14, 2006
  • #9
Thanks for the great wiring link!
 
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