rcollins17@sbcglobal

2006 f150 king ranch 150k. new alternator - after wire in door broken- new battery after alternator installed. Check Charging system light comes on every now and then also slight grinding noise under hood that is not constant- seems to happen when check charging system light goes off. alternator checks out and so does battery- any help will be rewarded with many thanks. STUMPED.

Marc D

Your idler pulley may be bad. When the alternator engages (electronically) it puts a load on the belt and can cause the pulley to grind.
The other place it may be is your A/C compressor. There is a very large electrical draw when it kicks the electromagnetic clutch on. A/C unit can make grinding noises even if its not bad. This can trigger a Batt. light. Your should be showing 13.5+ volts at the battery when the truck is running. If not the voltage regulator may be bad. Good luck

fordonly4me

Ok my alternator went bad killed battery as well replaced alternator and battery 1 week later my volt gage starts going to red on the high side with the battery light on and a grinding sound can't find anything wrong replace alternator again its good for like 2 weeks then starts again can't find anything wrong take it to ford it doesn't happen while they have it all diagnostics check out then I find the fuel pump module above the spare tire all kinds of corroded it wasn't acting up but I replaced that hasn't happened since it's only been a day though my therie is that there was some kind of electrical surge from the module being corded so bad into the electrical system but we'll see