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alternator question

Try disconnecting the field wire from both alternator and regulator. Turn on ignition power and test if either end of the wire has voltage. It should not have any.
If it does, use electrical tape to cover the terminal ends, and run a new wire directly from regulator field terminal to alternator field terminal.

Also, Looking at your chart, you also have excessive resistance drops in the wiring. Check bulkhead connections.
Checked the FLD wire and no volt. on either end with IGN on.
I did notice improvement after noticing new VR had a wider bracket and was landing on some weld. I swapped to old VR, cleaned off more paint behind bracket. I also cleaned dried oil deposit on BATT GRND at cyl. head.
Batt. volt. running was now 14.8-14.9 and at fuse panel I had 14.7. That's a big drop at fuse panel from previous 15.45.
Also, I saw 14.4 -14.5 at the IGN side of VR.
Do I continue chasing better grounds?
 
Also, Looking at your chart, you also have excessive resistance drops in the wiring. Check bulkhead connections.

There is just a bunch of resistance / voltage drops in the wiring.
Between the alternator output and the regulator input, there is a voltage drop of 1.4 volts! it might be the bulkhead connectors or the ignition switch.
To test, just jumper a wire from the alternator output to the voltage regulator input.

yeap, I’m agree that could be a problem hence why I mentioned earlier.


To test, just jumper a wire from the alternator output to the voltage regulator input. The regulator should now see the correct alternator output and regulate it down to the regulators set point.
Hell! That’s a good idea! Never had thought on that before
:thumbsup:
 
UPDATE:
so I ran new grounds from block to frame and batt. to fender. No difference, still 15.7 or so volts.
Then i noticed a 2nd wire off the batt. terminal of the ALT was boogered so I taped it temporarily and now I have
a solid 14.4/14.5v. This wire appears to go up to the horn relay and I have no idea why fixing it would make a difference.
20210518_172640.jpg
 
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