So my red top Optima keeps getting drawn down to like 6v and I can’t start my truck. My Kenwood amp today was reading 16.8v, would flash, then shut down. I pulled the amp fuse thinking I had an internal amp short and it was killing the batt. Well today it was dead again after work, while the amp was disconnected. I get a jump and go to leave and my low beams won’t come on? Only highs or fogs. My dash volt gauge is pegged to the right almost. Is my alt having a **** fit or something?
My head unit also turned off an on on its own twice right before all this started. Could I be pushing to much voltage from my alt and frying the headlight relay and possibly my amp? Not sure how to troubleshoot this. The Alt reads 17.5v output and the battery the same while the truck is running. Shouldn't I be closer to 14v? I have a 200A alt but it has never given my issues like this. Had it own for a couple of years now.
Ideas?

 

Both low beams were blown. Codes are p0178, p0717, p1518, p1638

The alt case has a slight magnectic pull but nothing thats gonna hold a screwdriver in place. Is this normal to be that weak?

 

Yea you're operating at way too many volts. It should be around 14.4 or close to it when the truck is running. It's possible the alternator could be going south on you. Another thing to consider, is have you done the big three upgrade? If not you could be creating a lot of heat trying to run a lot of power through the stock wires.

These are just a guess. I'm no electrical guru.

 

so when an alt starts to crap out it creates MORE power? I mean anything is possible just seems backwards. The internal regulator is crapping out?

 

Once again I'm far from an electrical guru and just throwing out ideas so take my words for what they are.

What made me think of it, was a lightbulb. When incandescent bulbs are about to go out they actually burn brighter for a short period. Couldn't tell you why.

Basically bottom line is try a different alternator if you have one.

 

P1638....Alternator Field (F) terminal circuit

Seems like I ve seen this before...the other codes must be old junk.

 

Replaced alt and headlights. All seems fine now. Crazy.

 

the alternator must have been taking a ****... Glad you got it fixed bro