I've finished my system upgrade in my 04 coupe:

Infinity Kappas everywhere
Two JL Audio e4300 amps
4080 box w/ 10W6V2
Original HU
Sirius tuner
ripped out Bose "amp"

Everything works great EXCEPT my AM radio reception went to hell in a handbasket. My amps are mounted on the back of the rear seat, so I thought maybe I was suffering from the "class D amp" problem (even though the JL e-series is class AB), so I've tried it with the seat down and up -- crap either way.

I've searched this forum and people refer to an "antenna amplifier" for the in-glass AM/FM antenna, but nobody seems to know where it is.

My Q: When I removed the Bose amp did I do something to affect the power to the AM/FM antenna amp? Where is this amp?

 

The Class D problem affects mainly FM.

If you are having an AM problem and FM is OK, my very first suspicion is that your antenna is not plugged in.

But it might be the amp - which I think is in the pillar - either is not getting power, or is being jammed by power supply noise. I know many older Clas AB amps made noise in the AM band. To find out, try pulling the amp fuses and see if the tuner will then stop on stations in "seek" mode.

 

People still listen to AM radio?

 

El Duderino,

Thanks for the reply. If I pull the amp fuses I cannot hear the noise ;-)

The noise is at the low end of the AM band (not everything is on Sirius on XM _yet_) and gets worse the longer I'm in the car, i.e., when first powered up, no noise, but after 30 minutes, almost unlistenable. It sound like oscillator drift, like the station is not quite tuned in right. It is definitely NOT alternator whine, as my noise happens even with the engine off (plus, I know way more than I want to about alernator whine, and this isn't it).

It's weird that I didn't have this problem until I mounted the two JL amps on the back of the rear seat and yanked the Bose amp out. I should have done one change at a time, but that's water under the bridge.

Is there some kind of power for the pillar-mounted antenna amp that looped through the Bose amp connectors? I just cut the wires to the Bose and taped them up -- maybe I should have spliced two together instead? I can't tell from the wiring diagrams.

Any ideas? Anybody else yank their Bose amp and get worse than normal AM reception?

 

when i swapped head units and added amps my fm reception got a little worse and my am got terribly worse with a high pitch whine as well. i have given up trying to fix it. instead i just listen to my ipod and screw the radio until someone can figure out this problem.

 

lol i don't think many