88 LSC Amp install... HELP

[eVole420]

I recently tried to install an amp in my 88 Mark VII and it has not been working correctly and I believe that it is power related.

It is a 400watt mono amp powering one 10" same setup i had in my old vehichle. It has an aftermarket JVC cd HU, the Ford Premium Sound amp is still installed and is powering the rear 6x9's that setup was working fine.

I ran 8ga double shielded with in-line fuse and and grounded it to a rear seat bolt, all fuses are fine. When i attempt to turn my car on it is not getting enough power and will make very odd sounds that I change each time I start it, odd yes.

The amp is putting sound to the sub and the x-over is working but its not powering the rear 10" the only power it is getting is from the HU, the power light is not coming on the amp.

I even tried to run a ground cable to the place where the factory amp is grounded. The only time i was able to get the amp to work properly is when i crossed the ground connector and the metal casing on the amp with a screwdriver on accident.

The amp is mounted to the box which is not grounded. So this confuses me more than anything and leads me to think the issue is not proper grounding but i cant understand why it would not ground to the seat bolt but would ground to the amp casing?

I dont believe it is the battery either it was just replaced within the last six months 880CCA.

All help is greatly appreciated.

[JoshMcMadMac]

You're amp might be shorted, causing an internal ground and screwing stuff up. Have you tested the amp?

[SQ_LSC]

Sounds like your amp chassis requires contact with ground along with the actual wire connection to ground. This is not totally out of the ordinary. Try grounding the chasis with a tight wire connection and see what it does then.

[eVole420]

Ok so just run a ground of the amp chassis to the vehichle chassis. It does not need to be 8ga does it? I have like 12" of 8ga cable and a whole bunch of 12 and 16ga.

[eVole420]

OK I think i got the problem solved, I ran a 16ga cable from the chassis of the amp to a good ground and the power for the amp popped on! Hooray! Now for the fun part, I guess that the lack of proper grounding or just pure dumb luck for me has now required me to purchase a new starter. It finally started making a consistent sound which I could recognize as the starter not disenagaging from the flywheel so I'll replace that and hopefully that will be the end of that problem.

Thanks for the help and I feel incredibly stupid for not thinking about something that simple.

Now my 10" verge(ha ha) gives my music a little more depth to it. :)