Hello Everyone,

Over the past few weeks I've been dealing with a ground loop problem and I'm on the verge of going crazy:wallbash:

3 weeks ago I decided to clean up my amp install which included a Kenwood 4 channel powering infinity kappa components up front and kappa coax in the rear. I have a RF amp powering and 8" kicker in the rear pass through. I have a LOC connected before the Bose amp. The bose amp is now in my closet. I disconnected everything, changed some cables, re-routed some stuff and BAM... noise. :scared:

I had originally run a 4 guage cable to the batt for power and another to strut brace for the ground. I subsequently ran another 4 guage to the batt as recommended by the grounding sticky. I used my fluke meter and .003 ohms as measured at the wiring blocks. Noise is dramatically increased. I regrounded my head unit and terminated it at the ground block in trunk. I replaced my signal cables from the Rockford Frostgate cables that came with the kit to monster home audio cables. Since my LOC is in the trunk, its a short run. Noise is now absent on my CD player and FM radio :)

Then I turned on the satellite radio. The worst noise yet. It is variable by volume and I can mute it with the mute button. OK, I figured I'll re-ground the sirius reciever to the ground block with everything else. Still noise! Almost completely unchanged!! I used the black wire in the harness that connects the unit in the trunk. I tried a separate ground in the trunk still noise!!!

I'm out of ideas!

I called Mazda the parts guy said it was likely my receiver that was bad and those $550 he said. When I worked on everything else I also replaced the factory sirius antenna because my reception was getting very bad. Reception is much better now. Could this have cause a problem? Any other suggestions? If I need to spend that much for the receiver I'll just replace the head unit. All help is appreciated!!! Thanks!!!

Additional info, the noise is definately alternator whine. It increases with RPM. I have a MS intake and exhaust, and the buzz overpowers the normally loud engine noise.

I also noticed something that could be helpful today, when I change channels, there is a pause while the stations change, during this short period of silence there is no noise. As soon as the new signal is tuned to, the noise is back.

Any ideas?

tonight I respliced the sirius tuner's ground cable back into the original factory ground. The hum is about 90% reduced. I was getting terrible hum from the same location last week....


I disconnected all the cables on the satellite radio tuner and tightened the zip ties that mazda installed to hold the unit in place. It the problem comes back I'll update the thread.