interference from window switch

slight problem, just noticed i am getting some interference from my drivers side window switch.

it only happens when rasing the windows, either of the four, but when controlled from the drivers switch. when i pull up on the switch the window goes up, and as soon as i release the switch i am getting a pop from my subwoofer.

i ran the power wire, the remote turn on wire and the external bass control (EBC) wire along the drivers side, and the rca's along the passenger side.

i have no idea what is causing this interference, but i want to fix it. the only idea i've had so far is to disconnect the EBC from the amp and see if it still happens.

please gimme some suggestions or else im just gonna go try and disconnect the EBC

ok, problem diagnosed...

it's definitely the EBC which is causing the interference, but i still dont know why. i unplugged the EBC and the interference was gone.

and i also discovered that besides the windows, the lock/unlock and the power mirror adjustment also cause it.

so basically i would like to get rid of the interference, which wasnt present before, and i dont know why it is now.

any ideas???

[Luc]

Try checking the ground connecting to the amp. The motors typically use a floating 12V to control the up or down motion, and I believe the mirrors likewise. But the door lock/unlock uses negative trigger, so any different ground potential could cause noises. The power cable may induce noise also.

so basically i should check the ground and power connections even though the interference is only going thru the EBC cable???

sorry im new to this, but it doesnt make sense to me. if you can explain it as simple as possible i would appreciate it

[Luc]

The EBC cable is just a typical CAT3 (phone line) cable. Can it pick up or induce noise on its own, no, but it can carry noise from the source, which is the amp. So yes, check all the power and ground first.

what exactly am i looking for?

[Luc]

Just retrace all the connections to/from the amp and to/from the subs. Heck, it may even turn out to be bad RCA cable.

1) Check to make sure wherever you have the ground lead connected to is clear of any paint, must be to bare metal.
2) Get a long enough RCA cable and just run it outside from headunit to amp.
3) If there's enough slack on the power cable, try to pull it away from the wire bunch near the kickpanel.

Installing is easy, diagnosing is the diffcult part. Whatever you can think of, just try it.

i am gonna check tommorow, but i still dont understand why the interference goes away when i unplug the EBC

someone please help me. i went through as much as i could think of. i checked and moved the ground, tightened all the connections on the amp, tested rca's, pulled power wire away and still nothing, the noise is still there, and i have no idea what to do.

someone has to have ideas as to what else i can try.

thanks in advance for any helpful advice

[cam2Xrunner]

Try running the EBC wire in the middle of the truck, and not alongside the power wire. maybe it's the same principal like the RCA's.

i tried that and am still getting the interference... how odd is that? i have no idea why the interference goes away when i unplug the ebc, but no matter where i place it i get interference from the driver side electronics.

after speaking to a very helpful mtx service tech he reccomended i place a snap on RF choke over the end of the EBC cable, as close to the amp as possible.

he explained that an RF choke is basically a filter, and is the same thing as whats found on the end of power or monitor cables... that inch long piece of plastic right where it plugs in.
he said that the EBC can act like an antenna sometimes and that its picking up the voltage spikes from electrical accesories.

im gonna go try moving the LOC, though i doubt it will work... if it doesnt ill just order the RF choke, which is only 7 bucks shipped.

[Luc]

I've seen that choke before even on regular telephone line cable (CAT3). While that may temporary solve the noise, but it doesn't eliminate the source of the noise. You can't just keep putting band-aids on something that just keeps bleeding. Isn't there another EBC cable you can try, if you haven't? A simple telephone cable that's long enough?

UPDATE:
it seems my problem is not what i thought it was. apparently the EBC is acting like an antenna, but the its not the cause of the noise. it is merely amplifying an existing noise. however the source of said interference mistifies me. tonight i disconnected the LOC completely as well as the EBC, and still have the noise.

in my n00b point of view im starting to think its something wrong with the amp itself. i bought the amp refurbished off ebay, and maybe it came defective. how else is it possible for there to be interference without the amp even being connected to the radio.

i tried leaving the LOC disconeccted and using the EBC as a distortion antenna. sure enough any electrical accesory i would hold the EBC up to would cause the noise. cigarette lighter, all 4 window switches, a/c controls, etc...

i am truly stumped, my next move is to try a different amp, as well as try my amp on someone elses system. if anyone has any advice its greatly appreciated

nick