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Alternator Drive Belt Broke


3 Different Drive Belts

The alternator drive belt (the one marked as A in the picture) broke on me. I’ve got a few questions. First of all the car has some strange electronic issues (windows rolling themselves down things like that) which I assumed wasn’t a big deal, but have heard it can mean there’s something wrong with the alternator. Now on top of this I’ve also had trouble with the battery being weak which I suppose (assuming there IS something wrong with the alternator) could’ve been due to the alternator (or the messed up belt I didn’t know was messed up). Anyways I hardly drove when the belt broke I parked right away in the driveway and it wouldn’t start back up which I would like to think is just the fact that the battery was already weak and now without the alternator belt on it couldn’t get any power at all (if it even works like that). The car is not worth much and I’ve got more time then money so I INSIST on fixing this myself. I would have to get it towed somewhere to get it fixed anyways which would really up the price too.

Regarding the three different drive belts: the one labeled as C seems to spin just fine, the part below that where the belt goes on the alternator also spins just fine, but im actually also concerned about the air conditioner compressor drive belt labeled B and it’s way down in the back and kind of hard to reach. I couldn’t get that spin with my hands and I don’t know if it’s suppose to spin freely or not. This being said that belt actually looked pretty worn too so I thought it may be a good idea to replace it too. Hell, maybe i should just replace all 3 of them. Anyways I’m really looking for suggestions and what else i need to look out for when replacing these belts (maybe not belt C it seemed fine im not sure what it’s for). Is it likely I will also need to replace the alternator?

First,bring the battery to a shop and have it tested.Cold cranking Amp is what they need to check. Replace the battery in case it test bad. Get a new alternator belt(GATES makes good ones) and install it.Crank the engine and see how it goes. In case the battery get discharded due to a bad alternator,replace it and see how it goes.Depending on the car set-up some alternators are easily installed but others are not.

Thanks for the reply it’s nice to have a kinda step-by-step on what to do/try. Anyways only other concern for my was the air conditioner compressor belt i couldn’t get it to spin by hand so my assumption is just that it won’t spin when the engine is off/the ac is not actually running and I’m having trouble finding a straight answer on that online or in the repair manual. If anyone knows for sure that would be great.

The A/C belt will not spin freely.

The AC belt needs to spin freely all the time the engine is turning. If it does not, the problem is with the compressor or the clutch for its pulley. If the only thing driven by that belt is the AC, you could remove the belt and drive on until you get the AC fixed.

The AC belt can not spin unless the engine is running.

As I read the OP, engine is not running and the belt is still on the compressor, not it should not turn at all under these conditions.


I looked at the diagram, and it’s obvious that none of those are serpentine belts

As such, you the driver must set the belt tension and maintain it

That said, is the belt tension correct . . . ?!

Too loose, and whatever accessory the belt drives may not work quite as planned

Too tight, and the bearings of the driven accessory may howl and wear out quickly


The a/c compressor pulley should spin freely without the belt on.When the belt is on and a/c OFF you won’t be able to turn it by hand. Its easy to recognize a bad a/c clutch pulley by the noise it makes when using your a/c. Usually the a/c will work erratically until it completely stop working and cooling the cabin.

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Of course!

If one belt broke, what makes you think the other two aren’t ready to fail?