Seems like everytime I install a sub and amp, I get some wining noise with revs or when I turn my blinkers on I here a small thud when it is first switched and also a thud when I turn off the car. How do I prevent that? Better ground wire? Better ground location? I can't think of what else it could be. TIA

 

1)make sure your ground and your power cable are the same gauge,if your using 4 gauge power wire,then you need a 4 gauge ground
2)ground cables should never be more than 18 inches long,the shorter the better
3)never run your rca cables from your deck on the same side of the car as your power cable,keep them as far apart as you can,with them being low signal,any interfearance they get will cause a whining noise
4)make sure that you ground your ground cable to a good location and sand it down and use a good size bolt
5)make sure the headunit is grounded to the chasis,not to the stock ground wire

nothing else i can really think of

 

I have the same problem and had a couple of questions concerning the response above. Is it really likely than the whine would be due to wiring the rca's and the power wire on the same side of the car. I have installed amps before and did this and never had a problem until this time. Also, is it also really a big deal being that I grounded the head unit to the stock ground wire and not the chassis. I too have done this before and not had this problem. My ground wire is kinda of long though and I am just trying to elimate the ideas that most likely isn't the reason. I used the same guage wire and sanded down a good spot for the ground in the trunk. thanks

 

i used to install high end stereo,it is highly likely that if rca's come in contact with some sort of outside energy they will make noise,depending also on the type of rca you use,you can actually move them in and out and hear the difference,at our shop we experimented with lots of things to improve our installs,this was one of them,dont run rca's too close to large power sources or next to the ecu,if you use a higher grade rca,you might be good,its always a good ideal to ground the radio to the chassis,you never know where that stock ground wire goes and whats grounded with it,most probalems always came from the units them selves,some one would bring in a head unit,used or whatever,we install it and get the whine,usually it was because the radio was previously grounded out and fried the grounds in the radio,not all the way so it still worked but enough to damage the circuitry and cause the whining noise.

 

Use better RCAs. Your system in only as good as the weakest link and your RCAs are just as important as your headunit, amps and speakers.

 

The whine is from the alternator, and is usually caused by a ground loop. The elctronics are not sharing a good solid, common ground. Run a single ground wire from the amp to the head unit, also be sure that the amp ground wire is tighten down directly to bare metal. Sometimes cheap, poorly shielded RCA cables are the problem as well.

A cheap fix is the ground loop isolator, $15 @ Radio Shack and $5 @ Frys..

 

That is correct it is alternator whine. It pissed me off once on my tweeter amp cause i used crappy wires. It now is solved

 

thanks guys, I was using smaller ground wire than I had for the power wire. I will change it out and see if that helps and also my RCA wire too. Real cheap RCA's I got from rite-aide probably aren't too good.