Alternator wiring?

I am trying to get this truck up and running & the engine wiring harness has been chopped off. It has the big alternator on it (Leese-Neville? see picture) with a single plug with two wires coming from it, one green one blue. I'm switching over to a regular E/I instead of the ESC unit it once had. (All of that stuff was gone when I got it & nowhere to be found) Can someone tell me which one of the wires would go to the VR? I'm thinking the green but not sure. Was the blue wire used to power up emissions items that I'm by-passing? I don't want to fry anything by hooking it up wrong. None of the wiring diagrams I have, show this type of alternator. Any help would be appreciated. Thanks.

These are shots of the alt. Pretty sure it's original to the truck. Does anyone know what type it is & how I should wire it to the VR?

niceolddart said:

I am trying to get this truck up and running & the engine wiring harness has been chopped off. It has the big alternator on it (Leese-Neville? see picture) with a single plug with two wires coming from it, one green one blue. I'm switching over to a regular E/I instead of the ESC unit it once had. (All of that stuff was gone when I got it & nowhere to be found) Can someone tell me which one of the wires would go to the VR? I'm thinking the green but not sure. Was the blue wire used to power up emissions items that I'm by-passing? I don't want to fry anything by hooking it up wrong. None of the wiring diagrams I have, show this type of alternator. Any help would be appreciated. Thanks.

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niceolddart said:

These are shots of the alt. Pretty sure it's original to the truck. Does anyone know what type it is & how I should wire it to the VR?

View attachment 26244

View attachment 26245

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The alternator on the truck in the pictures is the Chrysler built 100 amp alternator (later revised to 114 amp), which was first released in 1975 and used through 1987. It's not a Leece-Neville built alternator.

The 100 amp alternator is wired like a conventional smaller alternator with the two field wires, but they are in the same insulator/connector due to the different field brush layout. The alternator uses a separate ground wire because it is mounted with rubber bushings. It is connected in you picture above the main charge wire. The yellow metal tag under the ground nut should have the 100 amp identifier on it.

To wire the blue and green field wires, use the following diagram to connect the green wire to the field (F) connection at the voltage regulator, and to connect the blue wire into the "Ignition Run" circuit which feeds the other connection, ignition (I), at the voltage regulator.



Note that the 100 amp alternator field current is higher than a smaller conventional alternator (~5 amps vs. ~3 amps), so the matching regulator should be used. The truck's original regulator, all Chrysler replacements since the late 1970s, and good aftermarket units are built to support it though.

Vaanth said:

The alternator on the truck in the pictures is the Chrysler built 100 amp alternator (later revised to 114 amp), which was first released in 1975 and used through 1987. It's not a Leece-Neville built alternator.

The 100 amp alternator is wired like a conventional smaller alternator with the two field wires, but they are in the same insulator/connector due to the different field brush layout. The alternator uses a separate ground wire because it is mounted with rubber bushings. It is connected in you picture above the main charge wire. The yellow metal tag under the ground nut should have the 100 amp identifier on it.

To wire the blue and green field wires, use the following diagram to connect the green wire to the field (F) connection at the voltage regulator, and to connect the blue wire into the "Ignition Run" circuit which feeds the other connection, ignition (I), at the voltage regulator.

View attachment 26248

Note that the 100 amp alternator field current is higher than a smaller conventional alternator (~5 amps vs. ~3 amps), so the matching regulator should be used. The truck's original regulator, all Chrysler replacements since the late 1970s, and good aftermarket units are built to support it though.

Click to expand...

Thanks for your excellent response. I wanted to make sure I wire it correctly. Hopefully, I'll have it up & running by the weekend. Thanks again for the help. Enjoy your weekend.