OK, here goes...went to the store last night and the truck has been running fine. Came out and when I cranked her up I knew right away something wasn't right, but it started and ran fine. Then I noticed right away at an idle, the radio would cut off. Give her some gas and it came back on. Lights go dim, heater fan slows down, etc. Then I noticed the battery gauge was reading normal when driving but as soon as you let it idle, it dropped full down in the red. But still charged back up with engine speed. Few minutes later while driving around the parking lot, she just died. Dead as a door nail.

Original alternator, and an Optima battery about 8 months old.

Alternator went ka-put right???

 

It's hard to just say yes without looking at it. I have a battery/charging tester, so it's easy for me, but I go through about an alternator a year on my 98 and I don't have any mods, especially any that put an extra load on the alternator. I finally bit the bullet and bought a brand new alternator from NAPA with a lifetime warranty, so I might still have to change it every year, but it won't cost me anything.

 

It sure sounds like it but, it could be other things, corrosion in the battery terminals etc.
go to an auto parts store and they will check the alt for you.

 

It wont run at all. I haven't tried to jump it, but for arguments sake, let's say it is the alternator...Jumping it off would only get it started then once it's depleated again, she will shut down again correct? Mudman...what the hell are you doing to go through an alternator a year??????

What do these things run these days also??

 

Realistically man power problems can stem from one or more of a multitude of things like the Battery Cables, Voltage Regulator, Alternator Voltage Regulator, Serpentine Belt, bla bla bla the list goes on and on sometimes.

It does sound like the alternator though so It's not to tuff to just rip it off and take it to the auto parts store to have checked. If it is the Alternator definatley get one with a lifetime replacement warranty like Mudman did. For our trucks it can range from about 129.00 to 210.00 depending if it's new or remanufactured (but mostly depends, as always, on where you get it); but check around, especially on eBay (there's alot of eBay stores out there now with some kickass deals)

You may even want to think about a heavy duty Alternator if you have any mods, or plan on getting any, that drain extra juice. I had to do something like that on a cutlass I used to have and I wasn't disappointed.

Good Luck

Oh, and you are correct: it definately will die a few minutes, if not immediately, after it's no longer slaved to jumper cables.

 

One more thing is: you want to recharge the Battery after installing the new Alternator and before starting the truck (the guy at the alternator shop will be able to explain better than I can with this keyboard).

 

pretty much how i found out mine was bad.

driving along, the radio would cut out after 5 mins of drive time. then it would hit a bump and WHALA! i got power for a few mins then it died again! talk about frustrated when its doing this out of town.

i bet you within the next week itll bite you in the rear

 

If you are able to jump start your truck just to get it running, you can take a multimeter to the battery and see if the alternator is charging your battery. Should be around 13-14 volts.

If voltage is reading low while running and your truck finally just dies, then in my opinion your alternator is bad and its running off the battery until its finally drained.

This happened to me a couple times in a toyota and a camaro. But in the camaro, the alternator bracket broke and the alternator fell off...what a fiasco that was. The camaro still ran though because it had a mechanical fuel pump and a separate belt for the alternator. Once it was running, it stayed running. Just did not have any lights or anything.

 

yep, charge your batt. before running the new alt.... this is because if you put a new alternator on a dead battery it will full field the alternator to put out max volts and amps and can EASILY burn up a brand new alternator.

 

Nothing, it's a bone stock Expy, but it does have front and rear A/C which my wife likes to run on high every time she drives it. I tried the eBay route once. Got a reman for $45. It lasted two months before burning up and had no warranty. That's when I bought the new NAPA. It's been on there for a while now with no problems so far. It cost me around $180.

 

I have had bad luck with alternators from Kragen and their counterpart Checker parts houses. Napa and Reibes seem to push a better product.

 

Ok.....I have a 94 f150 4X4 extended cab and I thought I was having alternator trouble, I tested the battery and it was charging at 12 then it would jump to 15, so I changed the alternator and now things seem to be worse. When I start the truck it sqeals and the volt meter in the truck drops to nothing. Only when I get it up 40 - 50 mph does this go away and the volt meter comes back to normal, but when I slow down the volt meter drops again. When I am going slow I can't even turn on the fan. I heard that the regulator has something to do with this but the alternator is new and the regulator is part of the alternator. Can this have something to do with the belt tension?