I've been searching around trying to find the solution to a problem with the charging system on a 2003 Ford Explorer.

So far, the vehicle was being driven when the charging gauge went down, lights became dim, and finally it died. After installing a new battery, the vehicle started right up only to have the battery light on, and charging gauge low again. It was driven a short distance to a place where we could work on it. My uncle concluded that it needed a new alternator.

I had no part of this until this point, where I helped install a brand new Remy alternator. After installing the new alternator, we started up the vehicle verified that it was charging at 14.7 volts, and my uncle went on his way.

However after driving the vehicle for a while, the lights, blower motor, and everything electrical started to pulsate bright to dim, fast to slow, etc. When this happened the battery light would come and go. The charging voltage would rythmically change from 14.7 to 12.8, back and fourth.

Since everything worked fine before, we decided to try another alternator. This time I put in a cheaper new Palladium alternator. Now the battery light stays on constantly, but the charging is constant at 14.7V. The vehicle does not pulsate as it did before either. Everything works besides the battery light being on.

Any Ideas?

Try another alternator?

 

This vehicle uses a PCM controlled alternator. I have seen parts store alternators cause similar problems. You may need to buy a Motorcraft reman.