Let me preface this by saying I'm not new to car stereo installs...now on to the story...
So Originally I had my sub amp under the driver's seat. Didnt want it to get wet if I found myself in deep water crossings, so I moved it to the back cargo area. I used a new 4 ga wiring kit, all the proper fuses, etc. The power feed was routed from the battery, thru the passenger side firewall grommet, under the plastic trim along the doorsill, up under the rear seat and to the amp. I was careful to make sure there was no pinching along the route. The amp is grounded to the bolt under the flat part of the seat)
Got everthing wired up, moved the rear seat into the upright position, and some sparks flew from what appeared to be the seat hinge (at the base of the back part of the seat). The sparks occured ONLY when I moved the back part of the seat. I immediately disconnected the fuse, removed, checked, and reinstalled the wiring to make sure none of it was damaged or split. All the wiring was fine...so I have no idea what could have caused the arc or why...
Everything seems fine now, no more sparks when the seat is moved, but I'm kinda freaked out by the whole thing. I wish I would have found some damaged wiring to indicate the possible cause of the sparks.
So I'm throwing it out to my fellow fjcruiserforumers! Any idea why this could have happened? Any ideas on further troubleshooting???
under any seat bracket is a terrible grounding spot. in your case, the seat bracket isnt sitting flush up against the floor, so when you move the seat position it causes the ground to move.
find a better spot for the ground, there are lots of them. sand down the paint to bare metal where the ground is going to be. mine is near the same area on the flat spot under the factory panel that runs across the bottom of the rear seat. drill it, and bolt it through the bottom the the vehicle. that is the most bulletproof setup you can go with.