Sub plays while stereo is off
 

I installed a BTA850FH in my nieces Mazda 3 Hatchback today. The bass level sounds good for the size of the car, but we are getting some extra noise from the tube. While sitting still the sub works great, after you start driving the tube starts to play extra beats, almost sounds like a comstant rolling thunder. Even when you turn off the radio the tube keeps playing. I used the FAST-9999 with the FAST-BTAH wire harnesses to conect it.

FAST - Radio
Red - Org/Blk
Blu/Wht - Yellow
White - Wht/Blk
Wht/Blk - Gry/Blk
Gry - Wht/Red
Gry/Blk - Gry/Red

I grounded the harness to a seat mounting bolt.

Any help would be great. Thanks.

Re: Sub plays while stereo is off
 

Relocate your ground wire to see if this eliminates the problem. Also check to make sure all of the connections at the headunit are secure as well as the harness at the FAST-9999 and the Tube. If this all checks out, locate another constant +12v power source.