Engine Feedback thru speakers

[aurora4088]

>:(This has got me at a loss people. I am a fairly skilled electrician. Went to UTI and all that for automotive . Now this problem only happens on occaasion but is getting more frequent. My right front speaker cuts out and instantly I here feedback that changes pitch with engine speed. Now I know that in my 96' BOSE system each speaker has its own in-line amp but when it works it works great so I really dont think the amp is going out. Does anybody have a schematic or any ideas as to the problem. For now I unhooked the speaker to prevent damage but most of the sound reaching my ear comes from that speaker . PLEASE HELP!!! ??

[sall]

Factory Bose Headunit or aftermarket headunit w/ Bose system?

Any[other] aftermarket accessories HID kit, etc?

All factory?

[wireless]

Well - Typically engine noise is due to interference on the signal wires. This is why in aftermarket stereo installations, you run the RCA wires on the opposite side of the car as the positive wire.

It sounds to me like you might have interference - Maybe a pinched wire somewhere? Check in the door wire conduit. Also, ensure that all of your connections on your radio are secure and tight.

[bobsblue95]

When I installed a bad Bose amp, I had whistling and hissing that sounded like AM radio. Whining would rise and fall regardless of engine rpm. If the whining is directly related to engine speed, as above, trace the wires and look for pinches. Also clean the grounds, they can make a huge difference.

[sall]

Yeah the noise is typically what's called 'ground loop'. I had to tie all CarPC and peripherals to the same ground to prevent ground loop. I'm not a fan of the isolators. Vehicles are pretty noisy.

However, I think we need more info on all stock, aftermarket or any aftermarket accessories installed.

[aurora4088]

Thanks for the info. I will keep digging around.

[nelson480]

The Aurora Bose acoustimass does not have in line amps for each speaker, rather the one lone amp in the trunk. If the problem persists you may want to route your own signal wire to the speakers in the doors

[bobsblue95]

Usually the hum comes in on low level lines, not the hi-level speaker wires.
Start by beefing up the grounds to h/u and amp, then if you still have a problem, start tracking the wires from h/u to amp. They run under the drivers side door sills.

[acecondor99]

It sounds like a low level signal problem! Probably in the amplifiers preamp or low level traces on the circuit board!
You can try tapping on the case, and see if that affects it!
Other than that, the amp should probably be bench tested