Need Alternator help

-
Joined
Nov 17, 2018
Messages
20
Reaction score
17
Location
Wendell NC
I need some assistance with Alternators. The V-belt set up that the PO had installed used a make shift alternator bracket, although it worked, it was just a mess to look at. So I purchased a serpentine kit from CFV Racing, the 8 rib serpentine kit for alternator only.

Small Block Chrysler Serpentine Conversion, Alternator Only

So I start to remove everything out of the way and when I get to the alternator, I find out that the PO had used a autolite alternator with internal VR. The serpentine kit supplies the pulley for the alternator and it is Mopar specific so I do not want to try to put this pulley on the old alternator since it won't allow me to use the external cooling fins already on the old alternator, I need to use a mopar alternator that has the cooling fins internally.

I found a few Powermaster alternators that have an internal VR and since the original VR is long gone, I want to keep the wiring the same. But when I was looking at the wiring from the old alternator, I see that there are 2 wires coming off a plug in pig tail connector on the back of the old alternator, one goes back to the Battery lug on the old alternator and 1 wire shoots into the wiring harness. This obviously is not using the original wiring harness to accomplish,

I found information on-line that says that this connector can have the #2 terminal of the pigtail running back to the battery lug to excite the internals of the alternator and the #1 terminal is used to connect to the dash warning light?

Wiring up the GM 10SI Alternator

At this point I got lost, I am not sure where this other wire is going since there is no dash light in my instrument cluster? I put a toner on it and I pick it up on the drivers side in a part of the wiring harness on a green wire that has been cut and a resistor attached between the wires for some reason. When I check my service manual, it says that a dark green wire in the harness is for horns. When I go inside the car. I pick the tone up on the black wire attached to a lug on the back of my instrument cluster for the alternator gauge, getting confused yet..I know I am.

When I get the Mopar replacement alternator with Internal VR, where do I connect the wire that runs back into the wiring harness that was coming out of the old alternator?
 
Last edited:
Actually originally the no1 terminal of the Delco went to the dash light/ and resistor which allowed the thing to charge if the lamp blew out. To do those right, you need to have a series diode. Original owner may have changed things..........if he jumpered the old Mopare OEM VR wires together, that would end up with a small green that comes on with ignition and which arrives at the alternator. That is what he used for excitation. The old wireing path was ----blue "ignition run" coming out of the firewall----fed the coil ballast resistor-------and branched off and fed the old regulator.........through the regulator -------out on green----and to the OEM field terminal of the alternator

In other words there is a small green origiinally ended up at the OEM alternator and a larger green/red? that was for horns

IF that is what he did you should be able to use same wire for the powermaster excitation if that is what they want, there

You have a link or photo to the Powermaster wiring hookup?
 
A good clear photo of what you have would be helpful
 
I have some experience with 1-wire alternators of Bosch type, mid 80's. They used an indicator bulb to get alternator started, the indicator was powered from key ON circuit, blue wire in your harness. The output of alternator, big terminal goes to battery +, case of alternator finds ground at brackets. I think more modern 1-wire might start without the indicator. Thinking the resistor found in harness would serve to start alternator without indicator bulb , the green wire connected to #1, at alternator.

Since your new alternator likely has more current capability than original, a #6 power cable from alternator output to battery may be required, and also bypass amp gauge and beef up wiring, add power relays.....

The green wire, not part of horn circuit originally went from alternator to regulator, it energized field, that function is done internally on 1-wire.
 
Sorry guys for the late response, wife had the whole weekend off and she didn't want to spend it with me and the car...you know the drill. Here are the pictures of the wiring, the first is the connector that was attached to the back of the autolite alternator. Red went to battery lug and the white spliced into the green wire. 2nd picture is where I found my toner going and the addition of something (diode or resistor) that's crimped between the green wire.

Img_190806114131335-1.jpg


Img_190806114152187-1.jpg
 
I've been looking at the MadElectrical diagrams:
Catalog
I just pulled the bulkhead connector off and there is some corrosion, not bad but enough to want me to try and clean them up.

If I perform this upgrade, can I just snip the off the white connector that was plugged into the back of the old alternator, heat shrink the green wire and then run a 1-wire alternator using the Mad diagrams?
 
The only real thing I have against one-wire alternators is that they need a MUCH larger charge wire to avoid voltage drop. This is because the sensing is right at the alternator output stud, and when charging, that wire will have some drop, so the battery end will be "down" in relation to the output stud, which will run at nominally 14.

Yes you can certainly do that.
 
What size wire do you recommend? And just to be sure, the charge wire would run from the Alt Batt post back to the starter relay?
 
You want as direct a path as possible between the alternator and battery. Some starter relays are wired differently. And, you want a big fuse in there. Gauge depends on alternator size. If you are going to run 60A or larger, I'd run no6
 
-
Back
Top