possible causes for battery light and drain after WOT pull

[SuperHO]

Pulled out of a parking lot and got on it through 1st gear. Moments later, hello lil red battery light. Moments after that, no AC. Then the radio died.

Drove approximately 4 miles home and shut it off. Checked the belt and It's good and tight. Try to start, death rattle from the starter. Went and ***** the battery out of my 95 and it fired right up, but still has a battery light glowing warmly in the dash. Confirmed that the accessories are in fact spinning.

Did my ******* altenator just bite it, or is there another possible theory I can chase?

 

[kevinspann]

Sounds like it shit the bed. Check all the fuses related to the charging system though.

 

[Liquid_force]

Yep, alt croaked.

My alt met a similar end about a yr ago.

I was leaving the turnpike toll booth and decided to stand on it for some reason -- I don't do that very often. Right about the time it shifted I noticed the dash lights got ultra bright and the battery light came on. Mine seemed to be a voltage reg failure because it was charging TOO high, not low.

I guess our alts have a tendency to fail at high RPM's.

Just to be sure - any of the chain stores (my local Advance Auto for example) will do a full elect system check for free.

 

[SuperHO]

True....gotta get it there, first.

 

[93markVIII]

I guess our alts have a tendency to fail at high RPM's.

alternators in general don't like high rpm. i've toasted a few at 6500 rpm in other things. underdrive pulley is your friend.

 

[SHOZ123]

Most v8 SHO alternators that aren't original are for the Windstar and the pulley is smaller than what came on the original SHO alternator.

 

[kevinspann]

...which means it spins faster and is killed quicker.

 

[98SF19]

What about running a UDP along with the smaller alt. pulley? Are they close enough to cancelling themselves out to not worry about leaving the smaller alt. pulley on instead of putting the stock SHO one on it?

 

[SHOZ123]

First you need to see if the one you have is the same size. It's easy to change the pulleys when the alternator is off the car, as long as you have an impact wrench. But I'm sure plenty of V8 SHOs are running around with smaller pulleys.

 

[98SF19]

True. I was just talking hypothetically. Are the pulleys on these non-OEM alternators all the same size for the most part? If so, simple calcs can tell you the net increase or decrease of the alt's rotat. velocity when running UDP.

 

[SHOZ123]

I don't think there was a great deal of difference maybe a few millimeters in diameter. TrasGo use to have all the info but it looks like they are now hiding it?