Black Maxima

I replaced my broken alternator with one from AutoZone last weekend. The car ran fine until today. I'm leaving the mall with my girlfriend and I notice the brake and battery lights are on again. So I decided to race right home. I started to smell something that smelt like chicken. Then I saw smoke comming from under my hood. So I pull over and open the hood. There was a lot of smoke comming from the holes in the alternator. And I saw orange underneath the alternator which looked like flames. I called AAA and they towed my car to my house. I put another alternator from AutoZone on my car tonight, but the idler pulley bolt broke.

Another thing is ever since I got the car, if I have the ACC on with the radio playing the battery would start to loose voltage quickly. After about half an hour I would have a problem starting my car. I cannot keep the ACC on for very long without my battery draining. It only takes about 30 minutes with the radio playing quietly. I can tell when the voltage is getting low because I hear a fast clicking from around the enigne somewhere.

Any idea about why my alternator was smoking?

Thanks for the help,
Aaron

Black Maxima

Bump For A Saturday Night Read.

djengr

You may want to start by making sure all the grounds are in tact and check connections. If you have a loose connection somewhere it could cause a voltage drop accross that connection. If you are having a low voltage the alternator would need to generate more amps to keep up. Just a WAG.

Black Maxima

I noticed my positive harness (red) at the battery was loose.

dgeesaman

iTrader: (10)

1) You had the belts too tight.
2) Autozone alternators might not be worth a s**t.

Black Maxima

Give me some tips on how to tighten the belt. I tried tightening it until it didn't squeak on start-up, I guess I went too far.

Zach95SE

iTrader: (3)

I don't think it has anything to do with AutoZone alternators. I have had one in my car for a a little over a year and didn't have any smoking. Maybe the tensioner pulley froze up? I had a little bit of smoke when that happened.

streetzlegend

iTrader: (8)

iv had one from autozone for a few months now. and no problems. perhaps you tighten the belt extremly hard. your supposed to be able to turn the belt just 90 degrees, if the belt passes 90deg then tighten a lil more, n keep trying, if its completly stiff that u cant turn it at all, loosen it. on the hanyes is says this.

Black Maxima

Seems like I had to go pretty tight to stop the belt from sqealing.

NoMax...yet

iTrader: (3)

peer pressure

clive

None of the above know why your alternator was smoking. I do. I've had two car fires for precisely the same reason - you are very lucky to have got away with it.
What happened was that you had a diode fail short-circuit in the rectifier module. Current flow went into reverse; the battery was pushing dozens and dozens of amps through the charge wire and through the relevant rotor coil. The glowing rotor was what you saw. You're very lucky the current did not melt and set on fire the external circuit and set the harness alight, which is what happened in my case.
Car charging circuits are prone to this type of failure. Everything relies on the integrity of the diodes. There is one way to prevent this possibility: install an in-line fuse in the charging wire, rated at whatever is the maximum current your alternator is supposed to supply, plus 20% more.

Black Maxima

Hey clive, thanks for the reply. I shut the car off as soon as I could because I didn't want my car to blow up. I have a couple questions. Where is the rectifier module and what does it do? Besides installing an in-line fuse, can I replace a part? My alternator (ALT S.) fuse did not break. What wire do I put the fuse on? The thick, positive wire on the top of the alternator?

Any more information would be appreciated.

Black Maxima

Bump!!!!!!!!!!

the_3d_man

iTrader: (1)

it's built on to the alternator
replace the alty. prefferably by throwing it through the window of autozone. like in that discount tires commercial...

Black Maxima

Ok, so you guys think it's basically just an alternator problem. I hope my belt was not too tight. I will make sure I don't over tighten it. I will let you guys know what's up once I put my new idler pulley on tomorrow.

dgeesaman

iTrader: (10)

If you tightened the belt as you said you did, I doubt it was overtightened. I think Clive answered this 100%.

Dave

Black Maxima

Cool, thanks for the info!

Got any pictures of the in-line fuse on the alternator. Any idea what causes my charging system to malfuction?

clive

- Shutting the car off is not guaranteed to stop the short. Usually in fact, the alternator will burst into flames and ... you can imagine the rest. This happened to me on one of my DROF's, the vehicle stalled and smoke everywher. By unbelievable luck a fire extinguisher rep was driving past with a van full of extinguishers.
ANyWaY...
the rectifier module is inside the ALT. Basically the alternator is a three-phase (3 windings) AC generator and there is a diode pack in there that converts it into DC. Other than installing an inline fuse there is no protection against this problem. And yes, the thick positive wire is the one for the fuse. The rating should be:

(Max Alt power in watts/13.8) and then add 25-50% safety margin.

I suspect what happened in your case was less drastic: an internal short, possibly via the diode pack, caused just one winding to burn up. You were very lucky.

clive

One last thing. You asked what caused the malfunction.
No one can say. Poor components . . someone bought 3 containers of Chinese diodes and had to use them somewhere . . it was a hot day and your battery was low from running the hifi . . your karma has become too negative . . you buy products from questionable outlets . . ? add your opinion here

nadir_s

autozone = crap ... but good thing they come w/ lifetime warranty

clive

The lifetime warranty doesn't mean much when big red flames are shooting out of the front of your car and your wife is screaming 'we're gonna DIE!'
Take a good look at the next burned out wreck and think, "is that lifetime guarantee worth a sh**?" I'd rather have a car with no alternator than an alternator with no car.

Black Maxima

I just finished replacing my alternator and new idler pulley/belt tensioner. The car is so much quieter with the new pulley. There is no noise comming from the engine while at idle.

Thanks for the explanations clive! My girlfriend is the one that told me to pull over. HAHAHA