3G Alt help

[drizzie27]

Alright I got my Alt installed got is tested prior and 100% good. I got it wired all up according to the diagram in a couple post tossed the old harness and meter. I have Zero power. I checked my wires with a volt meter and got 12.4 v on my solenoid but nothing when I try to turn it over. I did have to ground my alt where the bottom bolt holds the alt in place, cause the small bolt I used behind the alt stuck out too far and wouldn't fit. Could my issue be with the ground how I did it? It's a 71 F-250 360cid.

followed this diagram
http://www.fordification.com/galleries/ ... nstall.jpg

[SmoothJ69]

from what I understand having researched this same mod, the wiring diagram does not include the wiring for the power to the cab. check out the last post in this thread http://www.fordification.com/forum/view ... 1042ffbd7c

When wiring a 3g alternator on a truck with 4 gauges you will have to rewire the main power wire (Black/yellow strip) that goes into the cab of the truck to the battery terminal on the starter solenoid, as this wire is now in the original wire harness from the alternator to the Voltage Regulator and when you remove that part of the harness you will not have any connection to the battery = no power to anything on the truck...

I don't know what year they were talking about or if it is still a black\yellow wire on YOUR truck but clearly something else needs to be connected.

[drizzie27]

Well I got it going, putting out a good 14.5v at idle. It has a slight squeal now at start up and when I rev it high really fast it will squeal also.

[71PA_Highboy]

That squeal is a loose or bad belt. The more load on the alt the more it will squeal... Which is on of the reasons they used serp belts on hi amp alts...

You can run a double belt and that will reduce the squealing...

[drizzie27]

it didnt squeal with the old and pulley though. and its about a 1/4 in play