I'm looking at the wiring diagram now and it looks like the only way the alternator connects to the battery on the positive side is through a post on the starter motor relay. The post on the alternator may have a label of bat but I'm not sure if it's an aftermarket alternator. The post should be the one facing the battery and connects directly to the + side of the battery.

You may want to check the ground coming off the alternator as well to make sure it's making good contact with the chassis as that's the other point of contact with the negative side of the battery system. The ground comes off the the ground post on the alternator and is spliced in with a cable running to the alternator regulator.

There are several wires that run into the car such as the fuse panel and ignition system. Have you checked the fuses?

Hope this helps.

 

nope both alts have the same shape to it

 

i have not checked the fuses but thanks that does help im gonna go check on it........i will keep this udated thanks guys

 

dang it should work then

Okay i again second the multi meter its only 20-30 bucks and its good for lots of things im sure youll be glad you bought it

Good luck

Gun

 

Not sure what year Mustang you have, but here is an alternator wiring diagram for the 65-66.
http://www.cjponyparts.com/TechAltWiring.asp

 

thanks i think my ground cable was connected to the sta instead of the ground post

 

If anybody else has any other ideas to why than please i could use all the help i could get

 

cool
Hope it works out

[edit] you did switch them right? Did you try the headlight test?

Gun