Alternator polarity?
I noticed, whoever rebuilds Napa alternators locally here, cuts that spade connector, so u cant plug it in on this roundback.
View attachment 1715552290
:rofl:
Presumably you unwrapped the harness to get that out.
That should be the smallest wire, but make sure there is no damage on the rest of the circuit going back to the battery.
I'd be most concerned about the column connector, and other connectors in between.
need to get the right wire to replace that section.
What gauge is it?
Look at the wiring diagram in the '72 shop manual.
The letters next to the wire will be something like J2A 18DBL. That translates
Run (Ignition 1) circuit. 2nd section branch A. 18 ga Dark Blue
I know the earlier cars, it was typically 18 ga for A-bodies and 16 ga for B-bodies. '72 might be the same.
Here's what I'd recommend:
Buy a couple feet of Blue insulated GXL from Wirebarn.
Get a new
Chrysler type terminal and an open barrel terminal crimper.
Put this terminal on the end of the new wire and transfer the original plastic housing.
example here
Get an open barrel splice terminal and heat shrink tubing.
Splice the new section to the original in the harness.
Shown here:
Inline wiring splice clips........from the Dodge RAM service manual
Some alternative methods
Clever splice
Rewrap the harness.
Done and it will be as good as new.
As far as the alternator.
if your place will take it back/exchange the bad one, do that.
Take your old one and clean it.
Take out the brushes and replace them, along with the insulators and insulating washers, if needed.
Brush ID:
Alternator repair, a little show and tell.
If it spins well - no looseness or tightness - run it.
On the bad one if they won't take it back.
Open it up and trace down where the field circuit is grounding out.
Its either a brush or terminals grounding, or the rotor is grounding.
If its the brushes and terminals, replace them.
If its rotor related, that will be a more difficult repair. We can help you tackle it or you can find a small shop to deal with it.
Replacement of a rotor involves removing and reinstalling the pulley.
Write up or guide available for alternator pulley install?
Another thing to check when the alternators are open.
Output terminal (big stud) is tight and and straight. It can only be tightened when the cases are apart.
It is also critical the stud is insulated from the case!
