Bad Alternator

bkfireman07 · Jul 20, 2012

Alright guys, my alternator is going bad/bad. Disconnected the negative cables off both batteries tonight and the truck died when I opened the drivers door and turned the headlights on. I've been having issues the last couple weeks with needing to jump my truck. I originally thought it was my batteries till my brother helped me check the alternator tonight. So heres the question should I buy a stock alternator or a aftermarket one? What would be the advantages of going with a aftermarket one and which one does everyone suggest. Thanks

AKHILF · Jul 20, 2012

Are you running anything extra? Like a bunch of lights, a big sound system, winch or inverter? If not i'd say just go stock again.

bkfireman07 · Jul 20, 2012

Eventually i'll have sound system, lights and a couple other ideas i got brewing up but not right now.

AKHILF · Jul 20, 2012

I have a pretty big system hid's some piaa's and an inverter. I do drop voltage when I have the system up pretty far but I think if your going for just a normal sound system and lights stock will be fine. But it never hurts to have more amps with your alt.

bkfireman07 · Jul 21, 2012

well its not the alternator, pulled it had it tested and it passed. Next step is getting the batteries tested

Zmann · Jul 21, 2012

Who told you to disconnect the negative cables with the motor running to test the ALT?

this isn't a model T

bkfireman07 · Jul 24, 2012

lol, my brother. He use to work at autozone an said thats one way to do it. Ended up being both batteries were shot

Mdub707 · Jul 24, 2012

Zmann said:
Who told you to disconnect the negative cables with the motor running to test the ALT?

Read my mind, I would never do that on one of these... everything on these needs some voltage... think about the FICM alone...

Zmann said:
this isn't a model T

LOL

Extended Power · Jul 24, 2012

bkfireman07 said:
lol, my brother. He use to work at autozone an said thats one way to do it. Ended up being both batteries were shot

What kinda batteries you runnin?

I went with Optima Yellow tops, but I'm not impressed.
I had a set of Optima Red tops before these yellow tops...and they were even worse...

I really don't think the stock alternator has enough jam to keep everything charged up...I even have the smaller pulley installed on it so it would be charging while driving in stop and go traffic. (Lower rpm)

I measured 110 amps being drawn with the headlights on high beam, heater fan on high, electric fans on high, engine at 1000 rpm.

Zmann · Jul 24, 2012

LOL I heard some D bag at Autozone tell a customer after they asked

"How do I keep from loosing all my presets when I change my battery ? "

Dumbass told them to

change the Battery with the vehicle running

Optima's aren't what they used to be ,, Autozone yellow tops or motorcraft large CCA's are good

as far as Alternators DC Power always gets My vote

Extended Power · Jul 24, 2012

I was gonna pick up a set of Odyssey PC 1750's but they won't fit in my battery tray. (The battery tray is made for Optima batteries.)

Zmann · Jul 24, 2012

I do like Odyssey batteries I run them in My watercraft ,, they even have directions on how to deal with a fully discharged battery ,, that would make a regular battery almost useless

Extended Power · Jul 24, 2012

Only problems I have with them are their price, and the fact that they won't fit.

They are double the price of Optima batteries.

Zmann · Jul 24, 2012

Ahh

I don't have any of the large Odyssey batteries he small ones are $110

I would rather have a lead acid than a Optima anymore

back in the day before they moved I had some blue top Optimas and they are still working fine but the yellow top I bought for my truck( other gasser) not long ago was a fail

Extended Power · Jul 24, 2012

The Red tops I had, made it almost 3 years, when the truck was just a ....truck.

These Yellow tops never made it 2 years, but I have had electric fans on, that draw 35-40 amps continuously.

Extended Power · Aug 17, 2012

Went to Battery Direct today and asked about my Optimas.
When I mentioned what I was seeing for charge to load factor, they asked me to wheel my truck into the shop to test everything out.

At an idle, truck hot, electric fans on, a/c on, blower on, fuel pump, daytime running lights and whatever else needs power at the time...the batteries had 12.6 volts, and only 3 amps coming from the alternator.

So the only thing they got is some 140 amp stock unit....I said no thanks...got anything bigger?
Nope.
So, now I'm looking for a vendor that sells either Mean Green alternators, or DC Power...

Anyone?

Zmann · Aug 17, 2012

hmm i don't buy the test

you'd have a batt light and wouldn't go very far

Extended Power · Aug 18, 2012

Zmann said:
hmm i don't buy the test

you'd have a batt light and wouldn't go very far

Well what I'm thinking is that while the truck is running, the alternator makes enough for the load plus a big 3 amps left over to go to the batteries to keep them up to charge...

Anytime I have the truck in the shop with the hood up...(which is alot

) I have the charger on them...starts wish better the next day.

Another thing that I think is hurting my alternator is the overdrive pulley on it.
Since they have a 3:1 or 3.5:1 rev ratio to the engine...4100+ rpm does it no good either...~12000 rpm on the alternator....

Zmann · Aug 18, 2012

Even the DC power alts have the small pulley SO idk ?

the 3 amps leftover thing ? IDK about that theory ??

Extended Power · Aug 18, 2012

Zmann said:
Even the DC power alts have the small pulley SO idk ?

the 3 amps leftover thing ? IDK about that theory ??

Yeah, but at least they admit to balancing them to 10k.

Shhhhh.....having the wife there when someone else says your alternator is no good, and you need to replace it......that there is a "you get to buy something for your truck again, and it's cuz he said so...not because you just want to spend money on it..."

I'm sure the alternator is weak...just came back from a 2 hour drive...parked it inside, popped the hood...batteries are at 12.6vdc.