I can't figure this out...

When I start my car, the PFC reads a bat volt of anywhere between 11-12 volts. Now, if I drive around without ever making any boost, the battery voltage does not charge - instead it slowly drops!

However, if I get the car into boost, the voltage will suddenly jump up to 13-14 volts, and stay right around that level.

I have a brand new battery, and a recently purchased reman'd alternator.

I went and had the system checked, and they said the testing machine reported an issue with the clip off the harness that connects to the alternator, but no matter what I do to it, the problem still persists! I've taken the connector off numerous times, checked the internal clips, cleaned the terminals, etc.

WHAT THE HECK???

 

Big Sexy T,

Perhaps it's tied to rpm, which spins the alt pulley faster. I'd swap out your alternator and see what happens, you may have a bad reman.

 

well i do have an underdrive pully on the alternator...but lots of people do!! no one else seems to have this problem...?

yeah i think i need to do that. what SUCKS is that the reman is gonna take more than a week to get in...and i'm supposed to drive back up to new york 1 week from today!!

RICH, HOOK A BROTHA' UP with one of those COOL GUY IRP ALTERNATORS!!!

 

Once the alternater is on, does it ever turn off again? By that, I mean, drop down to battery-only levels.

 

Maybe you should talk to the guy a couple post up trying to get out of paying a speeding ticket...he needs a better excuse..."but officer...I gotta make boost to charge the battery"...it has possibilities.

 

The voltageregulator is probably dying.
Or the belt is slipping, but you should have heard that.

 

Send us the alternator I'll look it over and have it do my 140 amp upgrade. The problem could also be in the wiring, such as the harness that goes to the alternator/starter/battery.

 

OK so last night i'm driving home...

5th gear, 60mph...voltage sitting at about 13v...

then suddenly, my dash lights get super bright and i look down and the voltage is at 15.9v!!!

i pulled into a parking lot and before i was even parked my headlights went out (blown bulbs)

now i'm really confused. bad voltage regulator? that's built into the alternator on our cars, correct?

 

Sounds like a bad regulator and yes it is internal. Stop driving the car or you are going to fry something. I melted down the entire body harness in one of my rx-7s once with a similar problem. The regulator gets replaced with my upgrades. Shoot me a pm I owe you a favor anyway.

 

Yeah, it definitely sounds like a bad voltage regulator. It should never get above 14.4 volts.(maybe slightly, but definitely never 15.9)

 

thanks for the feedback guys.

im taking it back to advanced right now...its supposed to be lifetime-replacement, so they should swap it out for free. i just hope it comes fast enough because im supposed to be driving from FL to NY a week from today!!!

 

Hmmm....

I always avoid the reman swap big stores, unless its for my s10 work commuter. Find someone that knows what they are doing. Not saying that the big box stores don't, they just don't have any personal investment.

Plus, if you are running an underdrive pulley, you really should be running an upgraded alternator anyways.