Truck is 2004 Lariat Crew 4X4, it has the 130A alt., replaced the alternator still getting no charge to battery, both old and new alt's test good off of truck.

readings taken with all accessories off and key in run position

Voltage @ Batt Terminals was 12.4V
@ back of Alternator = 12.4V
@ Starter Solenoid = 12.4V
@ Orange wire/wht stripe on Alt Plug = 12.4V

Now here is where it gets weird on the Alt plug the Green wire/Red Stripe, when the plug is unplugged from the alternator i am getting 12.4V, but after plugging it in to the alternator voltage drops to 1.4V

I am stumped ive checked every fuse/relay and fusable link i can think of but i cannot get the alt to charge or the batt. light on the dash to go off, any help is greatly appreciated.

 

thinking of trying this, found it on another forum, thinking about trying it, what do you guys think, heres the post:

I was having the same problem a while back. My mechanic worked on it for a day and a half trying to figure it out. He finally cut the wire coming off the alternator that goes back thru the instrument cluster to the idiot light and ran it straight to the fuse in the fuse box under the dash and I haven't had any trouble since.

 

How good are your battery posts, alt post and all your wiring. I suspect you have a bad charge curcuit or control curcuit. If your cable ends are corroded, then inside the cable can be, drastically reducing the cables effectiveness. May also be preventing charge. Try replacing main cable to battery from alternator. Be careful with above, you dont want to dry the alt, just check it for continuity or replace with a parralel new one to test.

 

It may be that fusible link or the mega fuse. How did you test the fusible link. Have you you tried by passing it with a mega fuse from alt to battery. I remember something about the fusible link being tricky to test. It may pass basic test but not the actual load.