is this my alternator?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=13730
Printed Date: July 14, 2025 at 9:32 AM
Topic: is this my alternator?
Posted By: Nokio
Subject: is this my alternator?
Date Posted: May 19, 2003 at 9:25 PM
I have a Power Acoustik HMR800-2X amplifier powering my Pioneer TSW31C subs. The amp performes well at all volumes, but when I step on my brake pedel hard enough for the brake lights to illuminate, the amp seems to lose power. I know this because the bass goes out and comes back in when I let off the brake pedel. Should I get some thicker power wire? Or is it a problem with the vehicle?
Replies:
Posted By: Big Purds
Date Posted: May 20, 2003 at 12:33 AM
it is hard to say what the problem is...
where is the power wire coming from? does it come directly from the battery or have you tapped into a power wire somewhere else?
it could be a wire size problem, but the wire would have to be pretty small to have a problem when the brakes are applied...there could be a problem with the alternator, that it is too small or unable to produce the amperage that your stereo needs...
these are just a few ideas, it is really hard to troubleshoot a problem that you cant see or hear...
Posted By: Nokio
Date Posted: May 20, 2003 at 7:01 AM
I have the power wire running straight from the battery, a brand new one (Die Hard), at that. I am gonna change the wires and let you guys know what happens...
Posted By: Nokio
Date Posted: May 26, 2003 at 4:33 PM
<bump> I "DO" need help here guys....
Posted By: bberman1
Date Posted: May 26, 2003 at 5:38 PM
This could be a hard one but here we go at night with your system off and engine running, turn on your head lights (low beams) and shine them on a wall. When you step on the brake do the lights dim? Also if you step on the accelerator do they get brighter? Also what size power and ground cable do you have? And how is it grounded? Also dose it also cut out at lower volumes, and is that the only amp you have? If not dose do any of the other amps cut out?
Posted By: sodamninsane
Date Posted: May 26, 2003 at 9:19 PM
Yeah it "could" be your alternator. Although thats a strange diagnosis. Turn on your headlights with the amps off, tap the brakes, hit the brights, turn on your AC, that kind of stuff to really see if your charging system can keep up with your car. Then turn on your stereo. Let it play normally, watch the headlights and see if they dim. leave a door open and watch the interior lights. Then crank your system and let it max out, if you see a lot of dimming or your car shuts off then it's def. your alternator.
Posted By: Pimpin93Cougar
Date Posted: May 27, 2003 at 12:02 AM
It wouldn't hurt to get an alternator when you have a system in your car. My lights dim when I step on the brakes at night, but the bass doesn't decrease. www.mralternator.com something above 100 amps, something like 125 amps or more.
I saw someone using a 16 gauge wire for a 600 watt amp. "Why doesn't my amp work?" "What size power wire you got?" "Just some spool of wire I got at Wal-Mart?" "Like from an amp kit?" "No, just some regular wire." "You $#!%^* moron! Get an amp kit!"
-------------
Posted By: wvsquirrel
Date Posted: May 27, 2003 at 1:24 AM
Little basic info...
Power Acoustik HMR800-2X
190 x 2 @ 4ohms
240 x 2 @ 2ohms
480 x 1 @ 4ohms
Pioneer TSW31C
SVC
100RMS
400Peak
I'm assuming you have two subs (you never mentioned the quantity). Based on your equipment, you should have each sub hooked up to it's own channel giving you apx. 190watts per sub. You should not bridge this amp with your current subs. You would be producing a 2ohm mono load which your amp is not stable at (being stable at 2ohms stereo is not the same as 2ohms mono). And since you have 4ohm SVC subs, you can either wire each sub independantly, wire both in parallel for a 2ohm mono load, or wire both in series for an 8ohm mono. But like I said, your amp is not listed as being 2ohm mono stable, so you should be wiring each sub to it's own channel.
I'd say run at least 8 gauge wire to the amp and an 8 gauge ground. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: Slackux
Date Posted: May 29, 2003 at 12:11 PM
If its not your alternator, here's a problem I ran into which seemed really odd, and similar to yours.
If you are sure your charging system is strong enough, check where you've grounded your amp. Once, I grounded the amp to a bolt that the brake lamps also happened to ground do, and for some reason when I tapped the brakes, the amp would cut out.
So, check your ground, it may be that simple. If that's not it, try grabbing a capacitor, if the amp isn't getting enough power when the brakes are pressed, a stiffening cap would provide it with those few seconds of power...
|