Wonder if anyone has had trouble with their charging system? My 05 Ex 6.0 alternator is putting out only 12.3v (bat terminal to neg.battery post). So with running lights and heater fan etc. running the batteries are discharging. Pretty soon they are low enough the truck won't start.

Bad alternator? How do you loosen the serpentine belt anyway?

Or bad voltage regulator? Is this the silver rectangular box mounted on the side of the engine blow the alternator?

Or other ideas?

 

The alternator is internally regulated. Take it off, run up to your local auto parts store that can test it and let them test the alternator. It sounds like you need a new one, but have it tested just to make sure.

To remove the serpentine belt you should see a tensioner pulley on the front of your engine. It will have a square hole cut in the bracket of the tensioner. That square hole is 1/2 inch. It is designed to accept a 1/2 inch socket drive. (Breaker bars work great for this, but a normal 1/2 inch socket wrench will work also.) Insert socket drive into hole, push against the spring until the belt goes slack and slip the belt off of the alternator pulley. Reverse process to install. There should be some sort of sticker in the engine compartment that shows the belt path and the location of the tensioner pulley.

 

Thanks Redford

I managed to get the alternator out last night. I took the batteries out cause I charged them most of the day and never got the little eye to turn green so I was thinking they were due for replacement. Once I had the passenger side battery out it was pretty easy to reach in and pull the belt towards the passenger side with my left hand and flip the little lever under the tensioner with my right hand to keep the belt loose (thanks to another post I came across about this little trick). I rigged up a medium length bungee cord up to the hood with just enough stretch to keep the belt in place and unbolted the alternator and slipped it out.

Got it tested this morning and sure enough it's dead. Got the batteries tested too and sure enough, they're bad too.

So a few hundred mastercard dollars later I'm on my way home to put her back together.

Should be laughing now, crying when the mastercard bill comes. Maybe my wife will like the new batteries as her Christmas present...