TXjeepTJ

iTrader: (8)

theres a plug on the back of the ls1's alternator that if it is not plugged in, it will not work

i think it is called the "exiter" or something


what is the way around this?

G-Body

iTrader: (4)

Are you swapping in the motor with the PCM and EFI or are you doing a carb swap? If your keeping the PCM what year is it and the wiring? The alternator is taken care of by the PCM on the 99 and newer. What is the alternator from f-body? Truck? Vette? Did you try the how to hook up an LS1 alternator link in the FAQ sticky post 13?

TXjeepTJ

iTrader: (8)

im just swapping in the pcm to run the engine thats it, im trying to run the connections that the jeeps alternator used to the ls1 alternator


alternator came off of an fbody, not sure what year though

G-Body

iTrader: (4)

Since the alternator is for an f-body you only need to connect terminal B of the alternator. (Of course you will also have to connect the main charging wire that goes to the battery too.)

I don`t know if you can use the wires that are from the jeep alternator. Terminal B must be connected to some type of resistance source and then to IGN + 12V. So you would have to connect the alternator to a 1/2 watt 470 ohm resistor and the other side of the resistor to IGN +12V. Or If you want to use a lightbulb you would connect the alternator to one side of the light and the other side to a wire that is hot when the ignition is in the run position (IGN + 12V).

TXjeepTJ

iTrader: (8)

i ordered a pigtail plug that plugs into that port on the back of the alternator, it has 2 wires- a black and a red one

red wire would be 12v going out correct? idk what theblack would be

G-Body

iTrader: (4)

It depends on what terminal the red wire goes to. You only need to hook up one wire (even though the connector has 4 pins). You need to hook up the wire that goes to pin B on the alternator.

The wire that you hook up does not go directly to 12V. If you connect the wire directly to 12V you will burn up the voltage regulator on the alternator, it MUST go through some sort of resistance, either a resistor or lighbulb.

TXjeepTJ

iTrader: (8)

ok, so when i get the pigtail, i just need to see which wire is going through the connector and touching pin B, i bought a 470ohm resistor to install in the wire that is going to the 12v source that is only on when the ignition is on

do i have everything correct?

G-Body

iTrader: (4)

Yep, you have everything correct.

TXjeepTJ

iTrader: (8)

i only have one more question, im going to be using only one of the wires going into the plug on the alternator, what do i do about the other wire? cap it off and leave it?


thanks

ALL UC2

iTrader: (4)

yep. make sure you put that resistor inline. we burnt up 3 alt. before i figured it out on here. yikes. autozone took them back though.

G-Body

iTrader: (4)

Yep, you can just abandon the other wire. Either wrap it with tape, or shrinkwrap the end, or you could remove it from the connector and fill the hole where it was with sealant.

george88gta

iTrader: (3)

I read thru the FAQ post you indicated and I noticed that you posted a question regarding the truck alternators and I could not find a response. Have you figured out what to do with the two wires (field duty cycle and indicator) that go to the truck alternator? This would be for a carbed LQ4, no PCM. The engine and alternator are from a 2002 Silverado 2500HD.

TXjeepTJ

iTrader: (8)

hey G-body, i just tested one of the original wires that went to the jeeps alternator with an ohmeter and one wire showed to be giving out 6volts when the ignition was turned on, can i use this or does it have to be 12vlt

G-Body

iTrader: (4)

I did end up figuring that out. Terminal B (indicator) goes to a resistance source just like the f-body alt. Terminal C (field duty cycle) goes directly to a 12V IGN + wire that is hot when the ignition is on.

G-Body

iTrader: (4)

I don`t think it would hurt the alternator to hook it to 6V, but it may not charge properly.

george88gta

iTrader: (3)

Thanks.

TXjeepTJ

iTrader: (8)

what im doing is using the 6volt coming from the ign. on and putting it to a relay that uses a 6volt to switch it over to send a 12volt to the alternator

TXjeepTJ

iTrader: (8)

wait, was i suppose to connect the 12v ign on to terminal C or B? i was told B and thats what i connected, i have an f-body alt.

george88gta

iTrader: (3)

The B and C wiring is for the truck alternator, not the F body. You should only have the one wire to attach to 12 volts.

G-Body

iTrader: (4)

You have it right, the f-body and truck alternators are different. The f-body requires 12V through either a resistor or light to be connected to terminal B

The truck alternators require 2 wires, the second wire goes directly from IGN +12V to terminal C.