My headlights are pulsating, seems to run ok. It's a 99' B2500. Are the alternators internally regulated? Thanks.
Charlie

 

May be alternator diode is bad and you got pulsation.

Your alternator has internal regulator.

Check battery too for density and level of electrolit.

 

Why not consider running this puppy by your favorite autoparts store, for a no cost, in vehicle, electrical system check up, via their portable electrical system tester.

Properly used it'll likely sniff out your problem.

Before you go, you might double check the B- body ground lead/s from the battery, especially the ones to the radiator support, as thats where the head lights get their ground point.

Let us know what you find.

 

Alternator regulator is probably gone. Rebuild it or get one from an autoparts store.

Ford Fuel Injection my favorite site for ford alts.

the 3g is so simple to rebuild if you don't force the case apart.

Further more, you can just remove the regulator/brush holder from the back of it, with the torx screws removed. Pin back the new brushes and stick the new regulator in, tighten the screws, and pull the brush pin, and install back on vehicle and your done..

the diodes are probably ok, the diodes are one way switches that allow current to flow out of the alt, and not back in.

 

Thanks, I'll check it out. It's prob. time, being 9 yrs. old and 181,000 miles on it.
Charlie

 

You did fairly well.

Most alternators last from 130k to 180k

Then you rebuild them with factory parts and get another 100k+

parts are cheap, but you have to dig around to kick up cheap parts.

like brushes are 2$ and regs are 20, but you have to look.