robTA

iTrader: (1)

i have a01 trans am . it has an aftermarket stereo with a mono amp for the subwoofer. never had a problem with the stereo till last year i put in an alpine amp that plugs into the back of the head unit to power the speakers. when the car is in park it sounds great and goes real loud, when im driving it seems like it doesnt have the same sound like theres not enough power to the head unit. the guy at the store said it was probably the alternator that when the car is under aload there isnt enough power. makes sense to me cuz im sure the car needs a new alternator anyway and i think it has been going slowly. my question is does this seem like the reason for the stereo to sound weaker to anyone? or is there also something else i should look at. the alt. is def bad i am replacing it soon, i barely drive the car. it has been starting slow and the voltage has been dipping low the handful of times i drove it the last year. just looking for another opinoin. thanks

Daniel Richards

iTrader: (1)

well for starters alternators output MORE amps (stock alt on these cars is rated 105 amp at speed and like 80 amp at idle) when at speed vs Idling, but when some alternators start to go heat from running will cause a reduced output, but the output wouldn't return after slowing down, it would have to cool off (as in car not running) to return to the higher output state. This is all based on my failing alternator.

You said you don't drive it much, letting a car sit for months at a time will kill a battery thats what happened to my car, the guy I bought it from didn't drive it for a couple months and I had to replace the battery. Have the battery tested at an autoparts store.

I can turn my system all the way up when driving down the road and not get a voltage drop, but when the car is under 1k RPM (stop lights or parked) the volt meter will drop like a whole volt when the bass hits.

robTA

iTrader: (1)

thanks, i was wondering if it was the battery i have a 2 year old red top optima, when i dont drive it i keep it on a battery tender but im not sure if that helps.you mite be right cuz it has been on the tender for a couple days and it still says charging not charged maybe i should jut get a interstate or something

Daniel Richards

iTrader: (1)

at 2 years your still under warranty, take it to where you bought it and have them test it and if it tests bad then get it replaced under warranty.

about 11 years or so ago back when I had my Tahoe, the battery in it went bad to where I had to get it jumped off everytime to get started but then it was fine except if you popped the hood and put your hand on the battery it was hot as ****, not burning hot but way hotter then it should've been.

Never really used a battery tender, but I also don't leave cars sitting for months without driving them, so I don't know how good or bad they are for batteries.

robTA

iTrader: (1)

thanks, thats what im gonna do, go get it tested. i think either way im gonna dothe alternator cuz the car has 98k miles on it now. the main problem is i dont drive it in winter and last year i got a harley so i only drove the car a few times in the last year. im gonna start driving it a lot more this summer tho. when i went to the garage todat the battery tender said it was fully charged so ill drive it a little and see what happens.

Daniel Richards

iTrader: (1)

I would definitely still do the alternator either way, I've been prepping for a new alternator myself. I got a Optima Red Top about a week after I bought my car because the original battery wasn't holding the trip odometer overnight (it tested at about half the CCA it should've been and it cranked fine everytime) and I've also done whats called the Big 3 upgrade because I'm looking to put a higher output alternator on mine when I get enough spare cash to replace it.

Plus stock GM alternators are weak and in my opinion undersized, I had a far smaller system (power rating wise) back when I had my Tahoe and the stock 105 amp died so I got a replacement from advanced within a year that one went out then not to long after that I sold that truck. I didn't have that truck for more then 2 years and it was on its 3rd alternator within 25k miles of me owning it. hell I don't think that truck even had 60k on the odometer when I sold it.