March 18, 2025, 10:47:47 PM

Author Topic: lt1 fc charging  (Read 3003 times)

Offline v8_7ryan

lt1 fc charging
« on: February 29, 2012, 07:26:59 PM »
I hope this is the right section to be posting this,  my engine is a lt1, but my alternator is not charging and I was wondering If I had it hooked up right. I have a 12 volt power from the Battery, and 2 brown wires pluged in from the harnes is w there anything I am missing I'm confused?

Offline mattster03

Re: lt1 fc charging
« Reply #1 on: March 01, 2012, 10:23:06 AM »
Which brown wires are you referring to?  I think I remember only a single red wire in a 4 point connector going to the LT1 alternator?  It's certainly possible they changed it for the later years.
 
The reason I ask is because I had to move that wire one pin over so that the alternator would charge properly.  However, IIRC this was so that it would not overcharge... not because it wouldn't charge at all.
« Last Edit: March 01, 2012, 10:28:22 AM by mattster03 »
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Offline Chuck78

Re: lt1 fc charging
« Reply #2 on: March 01, 2012, 07:30:50 PM »
Are you using the Lt1 alternator?  If so, Mattster is right.  I have done 2 Lt1 swaps, a 94 and a 95, and both were the same.  There is one red wire going to the plug on the alternator.  That wire needs to come from an ignition switched 12 volt source, then run through a 470 ohm 1/2 watt resistor.  This is because the alternator is looking for a 5 volt reference signal, not 12 volts.

Offline v8_7ryan

Re: lt1 fc charging
« Reply #3 on: March 01, 2012, 09:51:32 PM »
Yes its a 1995 caprice atlernator has a 4 prong plug with to brown wires running into the engine harness. Im not the best with Wiring....hey mattster would you be willing to head to sedro wooley to give me a hand sat or sun after noon around 4 ish just for some guidance? Pm me if your willing to help me out thanks

Offline Chuck78

Re: lt1 fc charging
« Reply #4 on: March 02, 2012, 11:32:37 AM »
I am actually using a caprice alternator from powermaster with my f-body harness.  I found a wiring diagram for the caprice.  You should be able to wire the brown wire going to the "L" terminal of the alternator as stated before. (this wire also runs through connector C205 pin"C")
Quote
That wire needs to come from an ignition switched 12 volt source, then run through a 470 ohm 1/2 watt resistor.
Then just disconnect the other brown wire going to the "F" terminal (or maybe "I" terminal).  This should rewire it like all F-bodys and work fine.

Offline v8_7ryan

Re: lt1 fc charging
« Reply #5 on: March 03, 2012, 08:49:15 AM »
Thanks chuck ill give it a shot today can I just go to any parts store for that stuff?

Offline v8_7ryan

Re: lt1 fc charging
« Reply #6 on: March 03, 2012, 09:06:36 AM »
Hey chuck could you possible post a picture of your setup?

Offline v8_7ryan

Re: lt1 fc charging
« Reply #7 on: March 03, 2012, 11:23:06 PM »
I am actually using a caprice alternator from powermaster with my f-body harness.  I found a wiring diagram for the caprice.  You should be able to wire the brown wire going to the "L" terminal of the alternator as stated before. (this wire also runs through connector C205 pin"C")
Quote
That wire needs to come from an ignition switched 12 volt source, then run through a 470 ohm 1/2 watt resistor.
Then just disconnect the other brown wire going to the "F" terminal (or maybe "I" terminal).  This should rewire it like all F-bodys and work fine.
Thanks chuck you got my alternator charging.... Thank you

Offline Chuck78

Re: lt1 fc charging
« Reply #8 on: March 05, 2012, 08:22:47 AM »
No problem.  Glad to help!  At first I didn't realize the b-bodys were different from the f-bodys.