this seemed like a simple solution. Last sunday I noticed the battery light come on on my 99 but seemed to still be running fine. I drove the truck about 30 minutes and the alternator started making a terrible noise. when I got home I went and bought a new battery hoping that would be the fix. when I put it in the alternator still sounded bad. Went to Ford this saturday and bought a new alternator. Slammed it on Sunday and the battery light was still on. Tested the system today and the alternator was not charging the battery. Pulled the alternator off and took it back to Ford and exchanged it. Put the new one on and same thing, not charging. Don't think I got another bad one so.....what does anyone have for ideas that it could be!!??

 

Poor ground.

 

went and checked the ground, found that the ground cable was damaged. replaced it with a new one. Problem still not fixed. Is there another way to test this? Could it be a fuse in the system? Anyone that could would be great.

 

throw a voltmeter on the battery while its running. how many volts do you get??your serp belt is ok right?? not loose or slipping??

 

Check the voltage on the small red wire on the alt you should have batt voltage if not check the fuse for the voltage regulator.

 

arent the voltage regulators part of the alternator these day?? they dont put them up on the firewal anymore fused seperate right??

 

Not sure about the pre 04 trucks but the current models regulators are built on the alternator.

I was thinking it might be the regulator as well since that battery light is a sign on the newer trucks that it's incorrect or broken if the alternator is working. I'd be checking the smaller wires that come off the alternator if you have those.

Anyways this is the wrong forum for this question. Might post over in the electrical forums.