Charging System Light

[bbayne35]

Hi,
I have a 2000 GT with 180000 miles. The short story is that my charging system light is flickering regardless of load or RPM.

The long story is that about a month ago, I noticed it would briefly flicker at higher RPMs. I had the system tested at Advance, and they said the battery and alternator were ok. The battery was installed in October 2013. The alternator was last replaced in 2010. I replaced the serpentine belt and belt tensioner, but I still noticed the occasional brief flicker. I also thoroughly cleaned the battery terminals and connections.

This morning, the charging system light has been flickering much more frequently. Like I mentioned, the load and RPMs do not seem to matter. I immediately drove to Advance again for a charging system test. The tech said everything looks ok. He suggested removing the alternator for a bench test, which I will be doing momentarily.

What else should I be looking for? I noticed when I put the heater on full blast while driving, when the battery light flickered, I heard the blower change speed. It sounds like there is a loose connection somewhere. Battery connections are good and strong. The nut on the alternator is tight and clean. Should I inspect the ground connections? If so, where are they? Thanks.

 

[bbayne35]

Correction...the alternator is actually pretty new. I replaced it last in September 2014.

 

[chasM]

Funny thing, I'm having the exact same problem with nearly the same circumstances. My 2000 GT has a Motorcraft alternator. I suspect it's original. At 185000 miles my battery lite is flickering as well. I have checked all connections and found no problems. I have researched this problem. I suspect a worn out alternator in my case. You might check out the two wire plug that goes to the alternator (voltage regulator) to start. I'll post back after I open up my alternator.

 

[chasM]

I reworked every connection to the battery and alternator but no help. every morning my battery light would come on for a minute. I rebuilt my alternator and fixed the issue

 

[picku]

Did you checked the wire between the alternator and your charging system lamp? Should be a thin wire. Its neccesary to build the first magnetic field to get your alternator working when it rotates.

 

[IH8BOWTIES]

Check to see if your headlights flicker also. You could possible have a bad fuse link as well. Two white wires that come off the side of the fuse block on the driver side strut tower that go into the one charging wire (black with red stripe) Also the one the picku speaks of is a smaller wire that has a fuse link as well coming off the same block. Fuse links get overlooked often.