Audio Systems: amp noise, alpine amp, antenna wire

Question
I have had a stereo in my truck, with the amp under the passenger side seat with no problems for about a year, recently my old alpine amp started buzzing in one channel. I replaced the alpine with an older fosgate I had to get me by till I could afford something new. When I put the fosgate in, there was a loud noise if I listened to a game on AM radio, that I never had with the alpine. I have sense replaced the fosgate with a new alpine amp (100 rms per channel when bridged) the noise is still audible on AM, but just barely when I first start the truck in the morning. But now I hear a popping noise through the speakers when I use my wipers on intermittent, if I turn them on regular speed or high speed there is no noise, only when they turn off and on. I have grounded the amp with a wire I think is about 10g and about 8 inches long. I have been told the shorter your ground  wire the better, is this true? I heard someone say that that the deck and amp should be grounded at the same place, that would involve a long ground wire. The place I have grounded the amp to is cleared of all paint for a good ground.  The deck is grounded through a wiring harness, so I am not sure where the deck is grounded. Any suggestions? Thanks, Larry  

Answer
Larry,
A 10ga wire may not be heavy enough to ground the amp correctly, and yes the wire should be as short as possible. The ground doesn't have the be grounded to the same point as the head unit. In most vehicles the AM radio will pick up electrical noise form the engine and wiper motors etc. Good noise filters and a double shielded antenna wire/cable will also help with good clean grounds at both ends. A good rule to go by with amps is to connect power and ground wires to them that are as large as possible that will fit into the connections for power and ground.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net