Check Charge Sys. Batt light.
Asked by Jason Apr 09, 2020 at 11:22 PM about the 2005 Ford Five Hundred SEL
Question type: Maintenance & Repair
I got a 2005 Ford 500. Just replaced battery and Alternator,
as well as serpentine belt and tension pulley. Battery light
and "Check charging system" comes on and off. Typically
when stopped or slowing. I did a test at battery. It
fluctuates from 12.9 to 1 to 15 to 18, and everything in
between. Help.
Please and thanks.
5 Answers
Start by checking for a wiring harness or connector issue at or near the alternator. Check for loose terminal in the connector. If you don't find bad wiring, this may be a bad alt.
So, I tested directly at the Alt. Same issue. About 5-10 min of idle and lights/AC/radio on, and random RPM runs at 2k. At start (and until batt light/check charge) volt @ Alt between 13.8-14.4. Then light comes on, meter reads 12.4.
Failed to attempt to trace wires thus far. I have a sub to alldatadiy, but having troubles tracking wiring diagram. This Alt is in such a ridiculous location.
Hey guys. So.....changed the plugs, and a c.o.p. due to a misfire, and all problems went away. Interesting.
