I know the 3G topic has been covered so many times. I think I've read everything. I'm out of ideas so I thought I'd try here. I'm doing the 3G in a 1977 F150 4x4, 6.6 400. The donor was a 1994 v6 Mustang, has two holes, etc. Changed the serpentine to the v-belt. Green wire is attached to green/red stripe, my truck has zero neutral amp gauge instead of the light. Yellow is doubled back to the battery wire.

New battery, new solenoid, professionally made battery cable with fusible link. A&B Truck Repair in Nashville, TN on Foster's made the cable for $14. The alternator was tested by Advanced Auto Parts and is good.

So here's my problem. I finally got the truck back running, long story I'll cover later. I had the green wire unhooked, and of course it wasn't charging. I think I understand this to be the "exciter", which I assume causes the magnetic field that's multiplied by the rotation of the other coils and magnets, and makes the current. When I hooked up the green wire, the v-belt started slipping so bad it made a huge cloud of nasty smoke and probably ruined the belt. Without the green wire hooked up, it very slowly ran the battery voltage down (with the new battery) even with lights on, fan, etc.

I've read some about doubling up to the main pulley, but that ruins my possibility of hooking the AC back up. Should I expect the alternator to take that much to turn it?

I've also read that some installations need a 560 Ohm resistor in series with the green wire. I know more about electronics than I do about truck repair. I wish I had a real schematic of what the regulator / alternator was doing so I could get a clear explanation of this.

OK, ISSUE #2, and may be related. On the starter solenoid, there's the S and the I. I understood the S is the starter wire, the I is an ignition boost. From the truck wiring schematic, the red/blue is the ignition wire, and I thought should go on I, and the brown wire would be energized to S to fire the solenoid. I may have this backwards, because that causes the solenoid to stick on. With just red/blue on S, and the brown wire disconnected, it starts and runs fine. I don't know if something with the alternator upgrade has improperly back-powered the brown wire when it shouldn't be? I've also Ohm'ed the ignition switch out and it appears to be working right.

I'm hoping someone can help me sort all this out. Luckily it's my toy vehicle so I can take my time, but I really am getting tired of messing with it! LOL

Thanks in advance.

PS - sorry for another 3G thread!

 

One belt is usually enough. Rule of thumb, one belt handles 100 amps. The 3g is ?135+ amps but it would be very rare for a Dent to pull that many amps so one belt typically works. If the alternator was "full fielded" by wiring or internal problem, it would make max output and drive voltage high and cook the battery, belt and other stuff. A really big battery in low charge state could cause the same problem. A loose belt could cause the smoke problem also.

Suggest you re-check belt tension, re-charge the battery and try again. This time with voltmeter hooked up to the battery. When running voltage should be max 14.5 volts. If it is higher, you have a wiring or alternator issue.