Alternator wiring issues

[67Dart273]

CHECK your wiring

We pretty much checked the output wiring in the above test. If the alternator charges in the above test, now test the field wiring. One of the field wires to the alternator should come from "ignition run" from the key. Hook your voltmeter to one or other wires, turn the key to "run." Should be "same as battery."

The other wire only goes one place....to the VR. Unhook the VR, turn the key to off, unhook the second alternator field wire. Check with a voltmeter that there is NO voltage on this wire. Now switch the meter to resistance (ohms) With the meter hooked to BOTH ends of this wire, there should be continuity---very low resistance

The remaining VR connection should have battery voltage on it with the key in "run."

The VR MUST be grounded to work

IF THE alternator charged in the earlier test, hook all wiring back up "normal." What you want to do now is eliminate the VR, and check the field wiring. Unhook the VR and devise a way to jumper across the two VR connections at that connector. A couple of small machine screws, etc.

Now go to the alternator and disconnect the wire coming from the key. This is the wire you checked earlier that has battery voltage on, with the key in "run." Rig a jumper from that disconnected alternator field terminal (the alternator not the wire) and ground it. Again run the engine, and the thing should rise in voltage and show a charge. If this is the case AND YOU ARE SURE the VR was properly grounded, replace the VR

 

[67Dart273]

GET AND READ a shop manual The guys at MyMopar spent a lot of time and likely money posting archives of service manuals. Some of them over there came from some of us right here. So go to MyMopar and download a service manual for your car. You may have to settle for Plymouth vs Dodge or vise versa.

Also there are aftermarket wiring diagrams, w hich are somewhat easier to read, sometimes, BUT WHICH sometimes leave out details and connectors.

 

[7duce swinger]

Is there a heavy black wire on the battery stud on the alt? Kinda looks like it’s missing. Kim

Yes it's the one in the picture, bottom right of my picture, under the blue field wire.

 

[7duce swinger]

CHECK your wiring

We pretty much checked the output wiring in the above test. If the alternator charges in the above test, now test the field wiring. One of the field wires to the alternator should come from "ignition run" from the key. Hook your voltmeter to one or other wires, turn the key to "run." Should be "same as battery."

The other wire only goes one place....to the VR. Unhook the VR, turn the key to off, unhook the second alternator field wire. Check with a voltmeter that there is NO voltage on this wire. Now switch the meter to resistance (ohms) With the meter hooked to BOTH ends of this wire, there should be continuity---very low resistance

The remaining VR connection should have battery voltage on it with the key in "run."

The VR MUST be grounded to work

IF THE alternator charged in the earlier test, hook all wiring back up "normal." What you want to do now is eliminate the VR, and check the field wiring. Unhook the VR and devise a way to jumper across the two VR connections at that connector. A couple of small machine screws, etc.

Now go to the alternator and disconnect the wire coming from the key. This is the wire you checked earlier that has battery voltage on, with the key in "run." Rig a jumper from that disconnected alternator field terminal (the alternator not the wire) and ground it. Again run the engine, and the thing should rise in voltage and show a charge. If this is the case AND YOU ARE SURE the VR was properly grounded, replace the VR

Should have mentioned I dont have the original key in column. How can I run that test now

 

[67Dart273]

Replace what I said with "whatever switch" you use to turn the ignition on and off, toggle switch?? Don't know. Here's a simplified wiring of the VR/ Alternator. It is pretty simple

Came from here:

MyMopar - Mopar Forums & Information - MyMopar Tools/Reference

Click "Wiring Electrical Diagrams"

MyMopar - Mopar Forums & Information - Mopar Wiring / Electrical

and click "Simplified charging system with dual field alternator"

MyMopar - Mopar Forums & Information - Mopar Wiring / Electrical

 

[pt70]

An excellent diagram Mr. 67 Dart, simple and easy to follow. And just to add a little for clarity, 'ignition 1' is the run position of the ignition switch. ----- 'ignition 2' is the start position of the ignition switch.