I mounted my soundstream amp onto the back of the rear seat in my civic. The amp is grounded to the seat belt bolt under the seat. When I push the seat back to close it I get distortion through the speakers. It happens when the metal latch touches the lock. Is this because the amp is all metal, has metal mounding screws, and is screwed into the thin metal under the carpet on the back of the seat? Will I have to just change to plastic screws or what?

 

i had my amp on my backseat for a long time and never had problems. You have me puzzled?

 

Seat belt bolts are usually pretty crappy grounding points.

Take out your DMM are measure ( impedance scale)between the negative post on the battery and ... where ever you are going to ground to.

If you find a spot that reads less than one ohm, it should be good.

A wire wheel will sand away any paint/ rust that is sodding your connection.

 

You have a bad ground.
SInce those parts are closely related in proximity it is beign conducted from the point to the lock.
Ground it to a new point.

 

is the location bad or is the paint making it bad? any suggestions for grounds in that proximity? the ground wire is only 2 feet long. i'll have to try that multi-meter thing. thanks

 

You don't really need a multimeter.
The seat belt ground is not exactly the chassis of the car.
If you have a drill, drill a hole in the floor of the trunk and ground it there.
Yes take off the paint.
It should be metal to metal contact.
it is a combination of the paint and the location that is making it bad ground.

 

grounding needs to be on metal surface. remove all the paint and that should fix your prob.

 

so i finally ground off all the paint from around the seat belt bolt. hooking up a wire to the negative side of the battery and testing with a multimeter it read at .5 ohm's. it still didn't work right. guess I'll have to drill my own hole. sucks.

 

yes, you need to find a new ground point.