Thanks for your help on this. Any opinion on simply disconnecting the sense/control plug on the alternator and leaving it off?

 

By disconnecting the plug for the I and A circuits your dash light will be off but by not having your alternator turned on I think the solution will be short-lived.

The third time, you need to check your diodes.

Install a new fused A (sense) circuit wire from the alternator plug to a positive source, even it's the + terminal on the alternator.

 

Will do the diode check. If it turns out to be bad diodes on new alternators, then what? If that's the case, I've had 3 bad ones in a row.

You're thinking what I'm thinking on the sense wire; just installing my own. I'm kind of stumped by the 3 fuses on that circuit. Do you think a 5 amp fuse on the sense wire is the right protection?

 

 

Ford did not use a 5amp fuse for the sense circuit. The last diagram, post 15.

Fusible links do not directly correspond to a fuse as they have different tolerances for the time at amps for interrupting the circuit. The 7.3L truck uses an 18ga fusible link, easily obtained from auto parts stores. Per Preece's calculation for an 18ga wire, it will burn in 10 seconds at 83 amps.

The 12ga fusible links Ford uses in the current supply cable from the alternator to the batteries will interrupt in 10 seconds at 235 amps. Each.

 

so some confusion on my part now.

removing the sensing connector on a SMART ford alternator is supposed to put it into DUMB mode.

SMART mode is 13.75 to 14.5 volts depending on air temps and other factors
dumb mode is 13.75 volts

so, the alternator is supposed to work with the connector off...but only put out 13.75 volts.

 

 

None of my Ford/Heim service manual diagrams show a fuse in the A circuit for a single generator truck. Those are dual generator.

 

Ford didn't start using that tech in the Superduty until 2008. This is 8 years prior.