Shelton63

My lights pulsate at idle. Figure the voltage regulator. Any advice on where to buy best replacement or other ideas on possible cause? Thanks

JTCHess

Mine does that occasionally and is not enduring as it is my understanding that this happens when the engine heater grids cycle.

John

Shelton63

This happens even after truck is warm. Thought grid heaters quit drawing after truck warmed up. Thanks

patdaly

FWIW, I had the same issue on Greenie, after about a year, the Alt. finally dumped. Replaced Alt. never happened again. That is a second Gen with the regulator built into the PCM, so I would say something regarding Brushes, Armature or diodes.

Same Alt is used across many Dodge products, just have to swap in your 8 groove pulley, if you have a good Junkyard, swap a gasser V8 unit in to try.

cougar

I recently went through this and a lot of unnecessary parts trying to fix it.
Try this, with the engine idling and a good load on the alternator run a jumper wire from the battery to the FSS (fuel shut off solenoid) terminal. This will bypass the ignition switch. If it eliminates the problem then the ignition switch is bad. The cause of my problems.

Rampage1967

Mine used to do this. During the process of installing headlamp relays i ran a heavy gauge ground wire from the engine block to the radiator bulkhead. The pulsing dissapeared.

Thunderhog

Check the bulkhead connector (on the firewall by the steering column) this is where almost all the main wiring passes from the engine compartment to the passenger compartment. There is probably evidence of heat, and corrosion on the larger wires (unplug it and look!)
The majority of the charging problems (like charging TOO MUCH) are found right here. I just hard wired mine right through the connector.
This is usually what causes the pulsing lights as well, it is a charging problem and has nothing to do with the lamp circuit.

rockmike

Interesting,my truck has a smoked PCM so Ive rigged up a toggle to ground out the wire for the grid heater so that works,I wired in a external voltage reg. for charging dutys.Ive run a seperate ground wire to the base of the reg and still have this same pulsing headlight issue myself.

Maybe swap the alt? I think my next action is to check that bulk head pigtail set up.Thaks for the info!