'05 3.0 not charging but no charge light?

[pentode]

Anyone happen to know offhand what the theory of operation of the charge fault light is on the 3.0? Mine's clearly not charging but no indicator light. Wife took the truck today, complained of the dash going nuts and the radio going on and off... Checked and the battery was down to 11 volts.

Put a little charge in it and it started and ran but voltage steadily dropping. Good b+ at alternator. Mainly wondering why the computer isn't complaining, I'm thinking that must be a clue to what's going on.

 

[franklin2]

There are some fuses and fusible links in the charging system. Here's the diagram for a 2005.

 

[pentode]

Thanks, that'll be super helpful!

 

[pentode]

It's the regulator. Still don't understand why there's no charge light coming on. I thought it was the PCM that turns the light on given some kind of feedback, current, voltage, whatever, but I guess there's something I'm missing.

 

[pentode]

Someone double check my circuit dyslexia here... I don't recall ever digging in to this style of regulator before. The brushes are as unevenly worn as they look, but I don't know if that's normal wear or how much travel they need.

The alternator passed the full field test (16V at idle) so... It's gonna be the brushes isn't it?

It doesn't appear they're serviceable. I might service them anyway.