will a 105amp be enough?

[no_username 2]

For my 750w amp?

[Jason Witt 65]

Ohm's law is invaluable.. Take the total wattage and divide it by your idle voltage. That will give you the amount of amps drawn to select a fuse. My calculation is roughly 60 amps. So yes, it's plenty.

[altoncustomtech 773]

That's good enough for a rough estimate. There's a LOT more to it than that, but he's right, you should be just fine with 750 watts on a 105A alternator. In my relatively short experience I've found that most stock electrical systems can handle up to about 1,000 watts without too much trouble. EVERY vehicle and situation is different though so you'll have to watch your voltage and see how it does. You should do a BIG 3 upgrade for good measure to help the stock backbone and be sure you have a good battery too. If your voltage drops badly, then you'll have to look at a solutions to the problem, if not then bump away happily.

[edouble101 314]

Are you asking about a 105a alternator?

If so, what else do you have hooked up? Keep in mind your vehicle can use the majority of the alternators ouput. If you use your amplifier at a low impedence more current will be required as well.

[edouble101 314]

Edit: double post, seems to happen a lot lately

Edited February 22, 2012 by edouble101

[Jason Witt 65]

That's good enough for a rough estimate. There's a LOT more to it than that, but he's right, you should be just fine with 750 watts on a 105A alternator. In my relatively short experience I've found that most stock electrical systems can handle up to about 1,000 watts without too much trouble. EVERY vehicle and situation is different though so you'll have to watch your voltage and see how it does. You should do a BIG 3 upgrade for good measure to help the stock backbone and be sure you have a good battery too. If your voltage drops badly, then you'll have to look at a solutions to the problem, if not then bump away happily.

I misunderstood the question a bit. He didn't specify alternator capability. I assumed he was trying to select a fuse size. Yes, there is more to it, but that was a short answer to his question.

[Jason Witt 65]

That's good enough for a rough estimate. There's a LOT more to it than that, but he's right, you should be just fine with 750 watts on a 105A alternator. In my relatively short experience I've found that most stock electrical systems can handle up to about 1,000 watts without too much trouble. EVERY vehicle and situation is different though so you'll have to watch your voltage and see how it does. You should do a BIG 3 upgrade for good measure to help the stock backbone and be sure you have a good battery too. If your voltage drops badly, then you'll have to look at a solutions to the problem, if not then bump away happily.

I misunderstood the question a bit. He didn't specify alternator capability. I assumed he was trying to select a fuse size. Yes, there is more to it, but that was a short answer to his question.

Double post.. Again OOPS

Edited February 22, 2012 by BrutalBasser

[no_username 2]

Only other upgrade is my alpine cde122 hu. Thanks

So with a multimeter is there a way to check for voktage drops when car running and stereo running?

[no_username 2]

Only other upgrade is my alpine cde122 hu. Thanks

So with a multimeter is there a way to check for voktage drops when car running and stereo running?

[no_username 2]

Whats the big 3

Battery

Alt

& what? My battery is just about a year old

[edouble101 314]

Only other upgrade is my alpine cde122 hu. Thanks

So with a multimeter is there a way to check for voktage drops when car running and stereo running?

Easily at idle.

You should be ok. As long as your alternator and battery are in good condition.

Do the "big 3".

[Jason Witt 65]

Whats the big 3

Battery

Alt

& what? My battery is just about a year old

http://www.the12volt.com/installbay/forum_posts.asp~TID~73496~PN~1

[edouble101 314]

Whats the big 3

Battery

Alt

& what? My battery is just about a year old

Lots of info, google it. Some helpful youtube vids available too.

[no_username 2]

Thanks. I hope i dont have to do that. I suck at mechanics and i never had to work on this car

So at idle how would you check for voltage drops? Just place mm leads on battery terminals? Should be at 12v if its ok right?

Oe will the amp draw some of the volts down?

[altoncustomtech 773]

The amp will draw it down on hard pulls such as a sustained bass note at full volume. You'll want to check it like that at the terminals of the amp for the most accurate idea of what's happening since the voltage drop will be worse at and on the amp than anywhere else in most cases.

[Jason Witt 65]

Thanks. I hope i dont have to do that. I suck at mechanics and i never had to work on this car

So at idle how would you check for voltage drops? Just place mm leads on battery terminals? Should be at 12v if its ok right?

Oe will the amp draw some of the volts down?

Measure the voltage with the engine running, determine your idle voltage, then turn your stereo on and watch your meter for drops. Edited February 22, 2012 by BrutalBasser

[edouble101 314]

Idle voltage should be +14v. Idle voltage is difficult to maintain that high with an aftermarket stereo on a stock alt. Doesnt really give you a good indicator of electrical system performance for your need.

You should be able to have a buddy hold your engine rpm's above 1500 while you measure voltage at the amplifier. There are other ways to measure voltage but I dont think you are ready for that yet.

[no_username 2]

So do i place leads on amp power and ground?

[djtomczak 5]

90 amp alt can hold my 1500w amp just fine. I only get slight dimming if I am running it full tilt for 10 mins at idle. And that's just slight dimming. As long as you have a stong battery under the hood you're fine.

AND the 90amp alt on my old taurus held 2250 watts total for about 3 mins before dimming. With a terrible duralast gold.

Edited February 22, 2012 by djtomczak

[edouble101 314]

So do i place leads on amp power and ground?

Yes.