My sisters 93 was changed to a external regulater, it charges fine but all the lights continuely pulses. You cant see or tell it the day time but at night the pulsing of lights are quite bothersome, any ideas ?

 

Well in the winter that is caused by the grid heaters cycling off and on. They may be malfunctioning, or it could be something completly different. I think I would un hook the temp sensor for them and see if it goes away.

 

mine does the same thing every once in a while but only whn the engine is cold????

 

I'm in the same situation. External regulator, lights constantly dim then brighten. It's the voltage regulator. There's a thread on here with a voltage regulator you can buy that is suppose to keep the voltage one constant number. Someone will chime in with it I'm sure.

 

If it's only happening when the engine is cold it sounds like a grid heater, but it should be warm enough in most parts of the states by now that your grids shouldn't be coming on in the morning. I think it has to be below 50 degrees for the grids to come on.

 

It does it all the time, not grid unless their working all the time.

 

Mine has been doing the same thing, all the time. The grids aren't on, they cause the guage in the dash to drop a bunch, and you can't hear the grids click on and off. My aftermarket gauges will jump also, Mostly my autometer tach and pyro. So any ideas?
DS79

 

First check the main feed into the bulkhead connector, probably cooked and high resistance.
Mine did the same thing as well. I had an overcharging problem on the road and fixed it with a relay on the hot side of the regulator to battery voltage. Key on activates the relay. Yeah, it was moused, but I was in the middle of the desert and charging like 18 volts. It has worked so well, 14.8 volts all the time, that I just left it.
The Bulkhead connector in mine was cooked as well. 20 years of corrosion, and heat in that connection cooks them. I just run a 10 gauge wire into the cab from the battery to the ignition switch and fuse box. fixed my power window and heater blower problems for good!

 

dont see it being bulk head on mine, it charges fine. it has to be in charging system imo.

 

This is a fairly common issue on all the older Mopars using that style regulator for some reason. I hear about it on other forums (cars) all the time and had it on my Duster. I don't even know how I fixed it, but after dinking around with it for years, cleaning/testing connections, adding new grounds, etc. it finally settled down and "almost" went away. I'm thinking in my case it was the alternator or a connection to-from the alternator, because that's the only electrical part I didn't replace along the way. I never got around to testing or changing the alternator after it eventualy seemed to sorta cure itself. Weird.

 

Every Dodge/Cummins truck we have did the pulsing lights until we replaced whatever various brand regulators they had with the BLUE MOPAR regulator part-number listed in my sig.

The wife's alternator recently had an issue that killed one of the BLUEs.

Not knowing what was happening, I borrowed a second BLUE from another truck and it immediately killed it also.

After swapping alternators, not having any more regulators, and the MOPAR BLUE ones having to be special-ordered, I picked up two $16 cheapies from ADVANCE and the pulsing lights came back; also, the voltage-gauge needle constantly quivers.

From day one, none of our trucks have the grid-heaters connected; all I see them as are useless battery-killers; so, none of our pulsing lights can be blamed on the heaters.

 

Hey Bearkiller, what was the problem with the Alernator?? Glad to see you got it fixed!

 

It takes 5 minutes to pull it apart and look. I think you will be surprised.

 

Here is what I did. I checked the voltage output at the Alternator while idling, and it was say 18 volts, then I checked the voltage at the battery, it was like 17.9 volts. Then I checked the voltage at the ignition switch, 12.4 volts. I then checked at the hot side ov the regulator 12.4 volts. The regulator was doing what it thought was right, trying to drive the voltage up because all it was "seeing" was 12.4 volts. The actual problem was the resistance in the main feed in the bulkhead connector. ALL the old Mopars I have taken apart have a melted connector at this terminal.
I knew what was going on, but being on the road, I needed a quick fix. Hence, the relay. I have NEVER had a charging system as steady as this one.
Try this, hook a jumper directly from the positive battery terminal to the hot side of the regulator and fire the Truck up. Then look at your lights. I will venture a bet they no longer "dance", as my kids called it.
Ace figured it out by cleaning all the connectors, and having good grounds. The main feed in these Trucks is marginal at best, then we add a bunch of power sucking accessories, add in time, corrosion, heat, etc. I can tell you they did not do this new, or I know my customers would have pitched a fit.

 

The problem hasn't been diagnosed yet.

I had an extra alternator and put it on the truck.

This "spare" alternator is charging good and, in the two weeks or so it has been on there, has not killed a regulator yet; so, whatever the problem was, it must surely be within the alternator.

I fully intend to get it figured out; I don't figure I "fixed" something, until I know just WHY it quit working in the first place.