a speaker is not going to cause you issues, a huge amplifier can cause a alternator to stress out if its pulling big loads ontop of everything else and the alternator trying to charge the battery all at the same time... alternators go bad over time. i suggest taking your car to a automotive center and get a free battery testing done, they can test alternator too if you take it off.. (in your question you state the car wouldn't start the first time but it did the second time)... that is not your alternator if this was a over night. and start up in the morning thing. that's a battery loosing its charge over night the alternator only recharges the battery while engine is running... now if that incidence was shortly after being drove and you just shut it off for a half hour or so then yes you have a issue with ethier alternator not charging battery or battery not holding a charge well at all., it may die over night cause bad cells or it may die within days of sitting not being drove, can also be a short in electrical like the radio... a alternator ethier works or it dont... it ethier charges or it doesn't. i typicaly unplug the positive cable on the battery while the engine is running.. hold onto the cable and do not let it touch anything at all... if the engine dies then the alternator is not functioning... if it stays running then obviously its working... because the vehicle should be able to run off the alternator alone. thats how i test a alternator but many people dont like that cause if you let it touch metal it can short circuit it and tear it up but obviously your not going to do that.... obviously if you unplug the battery and the engine dont die then its getting power from some where else cause it wont run off of magic.. batterys have cells in them... they go bad...... so i recommend getting both checked out for free at automotive store instead of playing guessing games with it. but make sure that belt is tight!

but definitely dont let water drip on it... that can cause it to short circuit and fail. thats obvious, obviously if the belt is slipping then its not turning the alternator to charge the battery... so yes those all could be key factors but a slipping belt will not destroy the alternator it just wont let it charge cause its not turning like it should be. it is possible you just have all these issues causing it. slipping belt definitely wont let it work haha... water dripping on it is unlikely but if it did then it would fry it.. so just keep the belt tight... dont let the water leak on it... and if it starts acting up again check the belt first and then the alternator itself by pulling the battery cable off... but id really like to see u get your battery checked also if you have a issue again cause i have a feeling it has some bad cells and needs replaced.

dont forget always make sure all your connections are tight and clean... no corrosion or rust. they need good contact.

Crappy vato-zone rebuilt parts store core swaps, get a good one the first time and this problem will go away.

Your belt is slipping . Your alternator can't do it's job if the pulley isn't turning .

A bad battery will destroy an alternator. The mechanic that repaired the first alternator missed something that caused the belt problem such as a bad pulley or belt tensioner. The battery should have been charged and tested too. Most after market alternators have a 1 year to lifetime warranty replacement policy.

Yes a lose belt and a home audio system will just make it sound really bad when it's turned up but the question I have for you is the battery at a full charge when the alternator was installed and the car was running because if not that just may be the issue also any part you buy from any after market supplier like auto zone if you can even get the right part their my suggestion for you is to go by the dealer and buy one from their make sure the battery is charged and the belt is tight

Wish you had listed the year make and model of your car. Box store electrical parts are terrible! Crack your phone book and find an AC-Delco parts store or distributor. AC-Delco alternators have a lifetime warranty. Every part inside the re-used aluminum frame is brand new. Not so with box store alternators.

If you have added an aftermarket amplifier the company who made it will be able to let you know how many amps. your alternator needs to be.

HI, if the belt is slipping then it won't let the alternator work fully. Get the proper belt and have the tension properly set.. Alternator light on and stepping on the gas puts it out is a sign of a slipping belt. don't keep going to the same shop.. sounds like there jerking you around..

good luck

tim

Within the past two, I've been through 3 alternators. My car had about 90k miles on it when the original went. It's replacement went about a year later and it's demise was abrupt and shut down within minutes of the battery light coming on (mechanic stated that he noticed my radiator hose had residue on it and could have dripped onto the alternator and shorted it out). About 8 months later, it's replacement started going bad but was still functional when it was replaced (this happened about a week after the fan belt shredded and knocked off the alternator belt). The battery light would come on but then turn off when i step on the gas. That replacement lasted four months when it gradually started to go again, car wouldn't start at first but would on a second try. Again it lasted until it was replaced, but the mechanic said the only thing he could think of that was wrong was the the belt was slipping which it was. I've been trying to be diligent to preserve this one by changing the hoses above it, and making sure the belt is tight enough.

I don't think it is a coincidence that they keep dying. Could it be speaker wiring? I don't have a major sound system although I did replace a door speaker with a regular small home stereo speaker. Could this make my alternator work too hard?

Any other ideas?