You may have checked this but if not a fusible link may be burned out leading back to your charging system. Some times they will not show any sign on being burnt on the outer rubber coating..
orich

 

Going all the way back to your original post. When you say you don't have power to anything. Did you hook the big Black/Yellow wire up to the battery side of the solenoid too. If you unplugged and removed all the original alternator and regulator wiring you would have disconnected the main power to the cab (Black/yellow wire). I know you said in other posts that the alternator was wired correctly, but some of the drawing don't show/mention making sure you hook up the main power (black/yellow) to make sure it's getting 12volts from the battery.

The 3g is very easy to hook up. Main 4gauge wire to the battery side of the solenoid protected with 175 amp fuse. Red/green to factory red/green. And extend the (main power into the cab) Black/yellow over to the battery side of the solenoid too, protected with an 80 amp fuse.

 

[quote=orich;11551271]You may have checked this but if not a fusible link may be burned out leading back to your charging system. Some times they will not show any sign on being burnt on the outer rubber coating..
orich[/quot

Again had the same though so I check voltage on the fusible link closes to start solenoid got 12 volts. I could not get at the one down by the alternator so I took off alternator stripped all the electrical tape and visual checked wires then checked all connections with a meter. Everything seems good so took off cover from voltage regulator no relay transistor control.

With the voltage regulator off (disconnected) I checked for voltage at the green/red and yellow wire connector, with the key on I get no voltage at green/red wire. Checked fuses at fuse box all the fuses were good (checked with meter)

If I'm not mistaken shouldn't I get 12 volts here even with the voltage regulator completely disconnected. Is't this the power for the field connector on the alt.

Oh 3g is out of the picutre for now as it was from junkyard and checked bad. I had my green/red wire to green/red on alt., power from starter solenoid to 175 mega fuse to bat. connection on 3g. The yellow wire from alt. I connected to bat. connection on alt. instead of going back to starter solenoid. Pretty sure this is right but if you see any problems with wiring let me know.

Anyway I'm head to the wiring diagrams so see if I can figure out why no power to green/red wire. Looking for any and all thoughs, thanks.

 

Ok making some head head way. Not getting power to green/red wirer I think I missed wired when I had wiring harness apart, going to check this morning. I think once I get power I will have a charging alt.

As said before I think the field terminal may have been grounding out and frying the alt. If you look at the alt. from the side you can see the field terminal sticks out slightly passed the bearing cap. Though it looked ok when mounted but really hard to see. I ground down all terminals and but a small piece of rubber behind bearing so it should be safe from grounding. These alt. IHMO should clock to 2 oclock to help with this problem.

3g I feel real stupid here but when I clocked the alt. I had to replace the brushes. When I did I forgot to take out the pin I put in that held brushes back for install. It was late when I installed them and was to lazy to get up and get a pliers to remove pin. Did not get back to it for a few days and forgot about the pin. Hopefully the 3g I have is still good!

Orich thanks for the idea to check field terminal would not have gone back to that so readily had it not been for post. The field ternimal is a real problem with these alt.s beware!

 

Third alternator clocked it to around 3 oclock ground down termals put apiece of rubber behind the bearing cap. I can now see terminals are not touching engine. Took complete cab harness off fixed any problems I could see and cleaned connections. Only connected ignition system starts up, got voltage to the green/red wire now. Still not charging took both the 3g and 1g in and both tested good. (I remembered to take the brush pin out this time) Bought new voltage regulator put in the 1g and new voltage regulator bingo getting a charging volt reading.

Not sure exactly what the problem was I know the first alt. had a low voltage output. The 2nd I think field terminal like orich said grounded out and maybe took out the alt. and voltage reg. Thanks for all ideas and help. Don't go to far from your computer I still have alot more work to do and will definitely have more questions!