This is more of a curiosity question than a problem. I have an 84 Dodge pickup that I bought 3 years ago for $300. All of the lights (head, tail, dome, dash, etc.) have always pulsed at the rate of about 2 or 3 times per second. I recently replaced the alternator and regulator and the lights are pulsing much more noticeably now. (I had suspected that the old alternator was weak for some time.) It doesn't bother me, but I was wondering why they are doing it. Anyone know?

Maybe a bad ground?

Years ago, I remember that once you installed a new separate voltage regulator you had to polarize it by creating a spark. Read the instructions that came with the regulator and see if you need to do that. Below is what I'm talking about:

Polarization is a procedure which matches the polarity for the generator and the voltage regulator. The majority of the vehicles are manufactured negative ground although some of the older vehicles were manufactured positive ground. The generator has to be set up for either polarity. The generator will charge either way, however the voltage regulator has only one polarity. Whenever the battery is disconnected from the vehicle for any reason the polarization procedure should be performed.

The recommendation on how to polarize a charging system is the following: After installing a battery, generator, or voltage regulator, follow these procedures. The terminals on the voltage regulator are labeled with letters and this is where you will do the polarizing procedure. Both of the components will have battery power so do not start the vehicle or turn on the ignition switch before polarizing them. You will need a small piece of wire fourteen or sixteen gauge with alligator clips on the ends. Find the "B" terminal on the regulator and attach one of the alligator clips, find the "D" terminal and touch the terminal with the other alligator clip. You can touch the terminals a few times and it will produce a soft light spark. Under no circumstances touch the "F" terminal or any other part of the regulator or you could damage the regulator.

We're talking 1984 so it has an alternator and an electronic regulator, but I do remember doing that in the 60's.

You don't polarize an alternator. It works differently than a generator.

Years ago, I remember that once you installed a new separate voltage regulator you had to polarize it by creating a spark. Read the instructions that came with the regulator and see if you need to do that.

The instructions are long gone, but I know the store owner real well where I got it. He will dig out the instructions from another one for me. I will try polarizing it and see what happens.

Thanks

We're talking 1984 so it has an alternator and an electronic regulator, but I do remember doing that in the 60's.

You don't polarize an alternator. It works differently than a generator.

I will check the instruction before I do anything.

Thanks