So I've got the Fummins going and finally drove it at night and I notice the lifts "pulsing". I wired the factory dodge alternator with a mopar voltage regulator I got a the picknpull junk yard. So I wired it up with a ground from the mounting bolt to the alternator. First thought was need an extra ground, so I ran a wire from the same regulator mounting screw to the ground on one battery.

Any thoughts? Only thing I can think of is to get one of the "mopar heavy duty blue" regulators.

Oh check the voltage with a DVM and it drops to 14.4 then up to 14.8, also no AC voltage from pos to neg battery posts.

thanks!

 

If the Ford reg is still there, you could use it instead.

 

The 89 ford didn't have an external regulator that I saw, the alternator I believe was controlled via the computer. However I did have what I think is a ford regulator from my donor truck (was a ford also). If I can find where I pitched it and find a wiring diagram for it I may give it a try.

thanks!

 

My Chevy conversion did the same thing. The voltmeter fluctuated from low 14's to low 15's and the lights pulsated. I did all the grounding stuff you describe also. Turned out the voltage was unstable on the wire I used coming out of the cab from the ignition switch to the voltage regulator. I ran a temporary wire straight from the battery positive to the field wire needing the signal. The lights quit flashing and the voltmeter stabilized. Then I corrected the problem by tying into the ignition wire I used for the injection pump. Strange military truck wiring.