We put a 90 amp alternator from a 1990 Ramcharger into the Duster as an upgrade.

It is blowing voltage regulators, I have went through three to them in the last two days. When I check the Kragen/Oreily web site it shows the same regulator for the 71 Duster as it does for the 90 Ramcharger. Any idea what I am doing wrong? It seems to me that we must be putting two much voltage out of the alternator to the regulator.

Thanks,

Craig

Regardless of the alt potential output, it still only puts out what is demanded, up to 90amp. Sounds like you may have one of the field wires grounded my mistake.

ok will check it out!

Craig

Might disconnect the field leads & check the ohms on the 2 field terminals on the new alt compared to the OE one you replaced. It MIGHT be drawing more field current than the reg can handle. EDIT I think you spin the rotor by hand when your taking a reading for this.

What Robert said. Plus, with an ohmeter, check from the field to the case. It should read high ohms. If it doesn't, it has a short to ground and that is not good.
Craig