|  Need help ASAP!, Alt wiring | 
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|  Need help ASAP!, Alt wiring | 
|  Nov 7 2008, 06:19 PM 
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| Grumpy      Group: Advanced Members Posts: 2,722 Joined: 1-January 04 From: Bakersfield CA Member No.: 81  | 
				I'm at the track doing testing today(race Sat/Sun) so i can keep 3rd place for the season.  The car has a new painless harness in it with the stock Alt, it only has the big Pos+ hooked up. I think thi.s is why its not charging. Any help you guys can give would be hugh! Thanks | 
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|  Nov 7 2008, 06:33 PM 
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| Seeking round tuits       Group: Advanced Members Posts: 5,522 Joined: 24-December 03 From: Kentucky Member No.: 33  | 
				I don't know about the LTx cars, but on the LS1 there is a big positive wire and a little enable wire. The alternator apparently does not have any internal or external voltage regulator per se. Instead, the PCM monitors the voltage (presumably using one of its many analog-to-digital conversion channels), and enables/disables the alternator as needed to maintain the proper voltage. I would expect the enable wire to be pulse-width modulated, but I haven't probed it with a scope to verify. If the LTx alternators work the same way, you may have to swap in a "single wire" alternator. Grounding the enable would probably cause the voltage to go too high (possibly much too high when above idle). This post has been edited by sgarnett: Nov 7 2008, 06:36 PM | 
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|  Nov 7 2008, 07:41 PM 
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| Grumpy      Group: Advanced Members Posts: 2,722 Joined: 1-January 04 From: Bakersfield CA Member No.: 81  | 
				Anybody have Mitch or Glens #? I know that they install this harness with a stock Alt. I'm trying to Google it with no luck so far..... | 
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|  Nov 7 2008, 09:39 PM 
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| Member  Group: Advanced Members Posts: 98 Joined: 4-October 06 Member No.: 1,394  | Anybody have Mitch or Glens #? I know that they install this harness with a stock Alt. I'm trying to Google it with no luck so far..... From the wiring diagram at AllDataDIY and I relied on such to demod the harness in my 94. The stock cluster put 470 ohms between +12V and the alternator terminal "L." Should be through the secondary normally closed terminals on the master disconnect. | 
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|  Nov 8 2008, 03:27 AM 
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| Nothing says 'I love you.' like a box of Hydroshoks       Group: Moderators Posts: 5,284 Joined: 23-December 03 From: Granbury, TX Member No.: 4  | Anybody have Mitch or Glens #? I know that they install this harness with a stock Alt. I'm trying to Google it with no luck so far..... We run a heavy gauge hot wire, separate from the Painless harness, from alternator to a pass through lug on the firewall. That pass through lug piggy backs a couple things, like the starter and 12V for a couple relays to run fans. On the other side of the firwall, I have fuse panels and the battery cable attached. So this is the charge path from the alternator to the battery. I think the lug in the Painless harness is for the motor electronics. | 
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|  Nov 8 2008, 03:35 AM 
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| Grumpy      Group: Advanced Members Posts: 2,722 Joined: 1-January 04 From: Bakersfield CA Member No.: 81  | 
				Thanks guys, I got it fixed thanks to FRRAX, Google, and Alan Blain.
				
				
				
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