I have an 85 ram that had the lant six but now has the 318. It has a new rebuilt alternator. I had the alternator checked out by the company that rebuilt it and he put put the brushes back in and i reinstalled it and it worked for a week. Now it has went back to its original condition. It will not keep the battery charged and the battery is good. Somebody said it could be my voltage regulator, but i dont see the thing. I see the resistor, but no voltage regulator. Any advice would be appreciated.

 

Make sure you've got a good ground strap between the engine block and the chassis. The voltage regulator bolts to the firewall behind the air cleaner just off to the passenger's side. It's got a somewhat triangular looking rubber plug with a couple of wires and a spring clip holding it on. It's roughly the size of a deck of cards, little bit bigger, and when you get the two mounting bolts out the back side will be an epoxy coating.

 

There should also be a ceramic resistor Off white in color) mounted on the drivers side (usually on the fenderwell) that has two 2 prong plugs on it. If that is shot, it wont charge either.

I had a mechanic tell me that if you replace the regulator, replace the resistor at the same time and bolt them both down (grounded) before
you plug them up.

Clean all your grounds too.