Alternator problems on a 72

[03svtsnakevert]

I have a 72 F100 with the 390...I looked at the wiring diagram for the 72 showing the alternator, here is how I hooked it up:

Black--ground
orange--field
wht/blk--stator
wire from bat side of solenoid to bat connector

sound correct? The ALT idiot light stays on when the engine is running and it is not charging...I have already check the alternator and it is good...also, the connector for the wires is a black plastic rubber piece with the three wires coming out of it...it also has a metal tang that appears to have been bolted down but I don't know where...anyone with suggestions? I am going to replace the voltage regulator today...Thanks!!! Love the forum

[Thunderfoot]

Sounds right... Here is a better diagram for you it is the same for your 72... http://www.fordification.com/images/sch ... rging2.jpg be sure the voltage regulator is hooked up correctly and changing it is the next step alright.

[03svtsnakevert]

I think I found my problem...I had the wire with the fuseable link stuffed under the battery tray and it was not hooked up to power the VR...another question, I don't have any type of ground wire hooked to the alternator...is this necessary???

Thanks!

[Thunderfoot]

In that diagram I posted above, the Black - Red Striped wire (#26) is the ground wire for the alternator, it goes to one of the mounting bolts of the V-Regulator (grounded through the fender)... I thought you had that hooked up from you first post..?

[03svtsnakevert]

In that diagram I posted above, the Black - Red Striped wire (#26) is the ground wire for the alternator, it goes to one of the mounting bolts of the V-Regulator (grounded through the fender)... I thought you had that hooked up from you first post..?

I had a wrong wire on the alternator initially...too many of the same color wire...now, I have another problem...

it appears to be charging, but after it runs for 10 minutes, it will barely turn over and not start...scratching my head here...maybe the VR is bad???

[6T7Merc]

it appears to be charging, but after it runs for 10 minutes, it will barely turn over and not start...scratching my head here...maybe the VR is bad???

are you shutting it off and then trying to start it back up after 10?
maybe a bad solenoid if so...?
second opinion?

[03svtsnakevert]

well, I forgot to put the chassis ground on the motor...kinda feel stupid now...but anyways...works great! starts everytime and the 390 sounds good!!!

Thanks for the suggestions!!

[Thunderfoot]

Yep, them grounds will get ya every time.
Glad you figured it out and got it running/working

[willowbilly3]

I might be having a senoir moment but I thought the orange was the stator.

[Thunderfoot]

I might be having a senoir moment but I thought the orange was the stator.

Yep, must be a Senior moment...

Look at these diagrams http://www.fordification.com/images/sch ... master.jpg and the one I posted above http://www.fordification.com/images/sch ... rging2.jpg (it is missing the "S" on this diagram) at the back of the alternator, the post are labeled;
S= Stator = #4 = White - Black Stipe
F= Field = #35 = Orange
B= Battery = #38 = Black
G= Ground = #36 = Black - Red Stripe

The Alternator will have these same labels next to the posts too...