!973 GMC 6500 Wiring question pertaining to the alternator.

[Rally]

Hello; So the problem is the alternator doesn't charge. (The battery terminal can be connected to the generator terminal on the firewall to force it to charge only because the reference wire is connected to the battery wire on the alternator and the reference wire is hooked to the field terminal on the alternator to make it charge for now.) (It's not recommended since it drains the battery when the key is off and leaves the reference connection not hooked to anything or ground it your wire is grounded; which would tell your alternator to charge all the time and cause issues.)

Investigating the problem the two issues I found are that the brown field wire doesn't connect to key on power like ignition or any other terminal or ground. The battery wire off of the alternator doesn't connect to key on power or the battery firewall terminal, or battery but it is connected to the generator terminal.

This GMC 6500 has an ammeter in the dash. There's nothing obvious for wire damage. Where should I look next?

It has a 10SI alternator for future reference.

 

[exp500]

Voltage regulator still on firewall? You mentioned Gen terminal. I suggest you look at a wiring diagram or diagram what you are describing. I dimly remember my 74 1 ton conversion to 10SI and a HEI dist. I used keyed power to dist to trigger alt. The Amp gage is a shunt circuit from charge wire. (you need to find it) 10SI has the diodes inside so Batt term can go direct to Batt. If it was originally a generator or split charging alt with external voltage regulator then you have 5 wires. Where/what is original field wire?
Original alt i believe was 10DN a 4 wire.10SI a 3 wire.
another option - https://store.alternatorparts.com/10si-series-12-volt-negative-ground-alternator-conversion-kit.aspx
Hope this helps.

 

[SpareParts]

Try looking up" how to make a GM alternator self exiting" Not sure at all but it might help you out.

 

[LtTahoe]

they make 1 wire alternators