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#1
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DN Alternator charge wire upgrade question
My '70 GTO's electrical system configuration is completely stock, Including a DN style alternator unit. Anticipating future electrical needs like EFI with an electric fuel pump and cruise control among others, I'll be soon looking to upgrade my alternator. In researching the various threads already posted, almost all of them involved switching to more modern type units and how to modify the wiring to accommodate the switch - something I don't wish to do.
My goal is to use a more powerful DN unit along with a solid state external regulator. I know that various accessories will only draw what they need. The real question for me is how to incorporate an upgraded charge wire to handle the additional output in case of a depleted battery. The attached picture shows the "junction" of the alternator main feed, sensing feed to the regulator, charge wire to the bat post on the starter solenoid and fuse box feed. So, how can I best upgrade the charge wire in this situation? Can I run and additional "helper" charge wire directly from the alt to the solenoid? Or must I include the junction to keep the regulator sensing circuit "in the loop?" Would the GEN light on my dash still function? I'd appreciate any advice as I want to maintain a stock appearance and not have to cut up a perfectly good wiring harness. Thanks!
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Larry |
#2
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We usually run a 2nd 'charge' wire directly from the alternator to the battery
You can either run it in the loom with the existing harness or directly from alternator to battery.
Soldered on (after crimping) ring terminals on each end with the battery end under the clamp-tightening nut and the alternator end between the existing ring terminal and the alternator. Or you can use the extra lead on the positive cable, if not already in use, but make sure you get the connection right (soldered and shrink tubing over it). 10GA usually works well, although we've used 8GA on a few vehicles with big power draw. Temporarily running a 2nd wire direct from the alternator to battery is also a great diagnosing tool if you have any concern that the original harness is compromised. Good luck! |
#3
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Modern alternator with internal regulator
It it's most simple form here is a wiring diagram of how to wire up a GM alternator that has an internal voltage regulator.
When you have an older GM car that started out life with the 1960s era alternator that has the 2 wire plug-in on the back (white and blue) wires and a metal cover voltage regulator on the firewall. There are several different ways to wire a modern alternator to that harness. Everyone seems to have their preferred method but keep in mind; unless you have replaced the engine harness recently you are dealing with crispy-brittle 50+ year old wires to start with.
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Peter Serio Owner, Precision Pontiac |
#4
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Quote:
The car had been pampered most of it's life and the wiring harness is still surprisingly supple and flexible. I really didn't want to molest the soldered crimp junction if it at all possible. This way, the original charge wire still has a connection to the sensing wire going to the regulator which should allow that to function normally and I shouldn't have a meltdown if my 130 amp alternator is called upon to charge a dead battery after a jump start. Thanks again. One other thought though - the GEN light function on the dash should be unaffected, right (light on with key on but off when the engine is running)?
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Larry |
#5
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The extra wire won't affect the GEN light.
And attaching it per your diagram will work just fine.
Good luck! |
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