85 TPI to LS1 alternator

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Jan 10, 2010 | 05:11 PM
  #1  
Im going to be putting in a ls1 soon, and was wondering what do i do to get the stock charging system to work. Do i have to rewire my stock plug to the new ls based connector or what?
Thank you
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Jan 10, 2010 | 05:51 PM
  #2  
Re: 85 TPI to LS1 alternator
Ok from what i found, i just need to run a positive wire from the battary to the back of the alternator and then the brown wire goes to the wire on top on the alternator to my stock volt guage. Sense im going carb thats all i should need correct?
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Jan 10, 2010 | 06:51 PM
  #3  
Re: 85 TPI to LS1 alternator
Not for sure about that since the LS1s are FI and the harness has most of the wiring on it for that.
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Jan 10, 2010 | 09:35 PM
  #4  
Re: 85 TPI to LS1 alternator
99+ car alts have a single wire controlled by the PCM
Truck alts have two wires controlled by the PCM

The only additional hook-up is the output wire to the battery. 3rd gen alt wiring is part of the C100 gauge harness and can be removed
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Jan 11, 2010 | 12:33 PM
  #5  
Re: 85 TPI to LS1 alternator
So i just have to hook a wire to the battary and i can keep my brown wire that goes to the guage to show volts, sense im going carb with the ls1.
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Jan 11, 2010 | 02:06 PM
  #6  
Re: 85 TPI to LS1 alternator
The brown wire on the TPI alt just gets 12v IGN from the fan fuse. There is no wire going to the gauge. The gauge reads the voltage across the entire harness, not just the alt output

Keeping the LS1 alt with a carb will require an inline resistor to drop the voltage. 12v on a LS1 alt will burn it up. Do a search on ls1tech for that
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Jan 12, 2010 | 02:23 PM
  #7  
Re: 85 TPI to LS1 alternator
Ok, so i was looking on ls1 tech and im still confused. Sorry. So i need to run one wire from the battary to the back of the alt, the brown wire needs a resistor in the line to make the alt turn on and charge. Or iam i still wrong lol
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Jan 12, 2010 | 03:31 PM
  #8  
Re: 85 TPI to LS1 alternator
Thats right
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Jan 13, 2010 | 09:20 AM
  #9  
Re: 85 TPI to LS1 alternator
lol thank you
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