alternator going nuts!
ok, here's the lowdown on the setup: '00 honda accord ex V6... headend: alpine cda 9657. as for speakers, i have two pairs of polk speakers being powered by a 4 channel polk amp. i also have a JL W3 being powered by another polk 2 ch. amp. what's happening is im hearing a humming sound possibly being picked up by the alternator going into the speakers somehow. like a high pitched whine... everytime i accelerate, i hear it going weeeee like a goddamn spaceship. ive taken all preventive measures possible to avoid this problem (seperation of power and rca, wires, etc) and still hear it. can anyone tell me how to solve this futuristic whip?
_also, my battery and alternator keep failing, and i know its the stereo. question is, how to run two amps and all that good stuff while still keeping the electrical aspect of the car intact and functioning fine without buying a battery every 4 months?
bwaa, thanks for the unload and responses!:confused:
For your electrical system, that is very abnormal. Polk's 4004 and 3002 arent going to pull enough power to make your alternator and battery fail. I would get an Optima Red Top, the biggest one thatll fit in your car and a good alternator. Also, upgrade your factory wiring with some 4awg. Put 4awg straight from your alt to battery. Ground your battery directly to the frame and ground the engine block directly to the frame(theres usually a ground bolt by the alternator that you can use for that).
As far as your hum goes, its usually 1 of 2 things...ground or RCAs. Do you have an extra set of RCAs you can run over the seats directly from the radio to the amp? If so, try that, if it goes away you know you need to reroute/get new RCAs. If not, try regrounding it somewhere else. Dont use a bolt. Scrape off paint and put 3+ screws in it.
Sounds like you've got a battery drain taking your alternator and battery down. Its not a direct short or anything like that, but I had the same issue with my wifes car the last couple of months and it took down 2 batteries and an alternator with it. Yours could be due to your system's install or something totally unrelated not turning off with your ignition. Mine is happening on 2 different circuits, the door locks or radio fuses are the culprit right now. I didn't even notice it was a problem until the battery ran down during 2 different vacation weeks coming home to a dead car.
I used to deal with alternator whine more with two-way radio, but this should still apply...
All the other advice with checking your wiring/RCAs is great. It's recommended that amplifier ground wires be kept as short as possible. I would certainly check that stuff out. Once you've tried running a new set of RCA's and you're still getting alternator whine, then read on.
In the past, I've added small "filter capacitors" between the power and ground wiring going to whatever device i was hooking up. By adding a relatively small cap (perhaps ~4700uF) between the red (+) wire going to your amp and (in the case of car audio), chassis ground, you can help to filter the voltage ripple created by the alternator. Now, i'd imaginge that audio amps would filter this stuff internally just fine, but it might be worth a try. You never know how this noise is getting filtered by your components.
To add to this, it's possible that the alternator whine is affecting your head unit, which may be causing it to output the alternator whine on your RCA's. If that's the case, you'd have to have a filter cap on the power supply wire to your head unit.
I don't want you to start ripping apart your dash and start putting little blue caps everywhere, but i have seen those little guys help a lot with 50W two-way radios, which aren't really much different than audio amps. Just a little higher in frequency :D
Ideally, you could install a cap like this:
It's 5 bucks and you'd need 3 of them to be thorough. You can install one each on your amps and one on the head unit. The cap can be hooked up right at the + and - terminals of each amp. You can just shove the capacitor leads in there along with your power cable for the intial testing. With this type of capacitor, you have to observe correct polarity, or the cap will burn up, pop it's top, and start spewing noxious fumes everywhere (not kidding). The hard one would be to put it in with the head unit. You can connect the positive end of the cap to the power wire of the head unit and the negative end to your ground wire. This would help filter the juice going to your HU.
Again, all this stuff should be a last resort. I'm running my 99 Civic without any extra filters and i get absolutely no whine in my system, which is mostly Polk stuff like yours.
If you need more info on alternator whine, a google search on the topic might help as well. Hunting down noise can be quite a challenge.
My suggestion go to a Junk Yard pull a old Honda Alternator, get that one rebuilt by a Alternator / Starter shop. Do not exchange it for anything, you what this one back. Replace battery for a fresh 72 month battery, then replace it EVERY 3 years. You may never have a problem again.
BTW I would also add a large cap to your audio amp. But not before I replaced above equipment.
I had this problem and it was the RCA cables. Sounds like you have something a bit more serious though.