Fitting an amp in the boot of my TVR tuscan (fibreglass body).

I'm unsure of how good an earth I am going to get trying to ground the
amp onto the petrol tank (the only thing metal in the boot).

As with most fibreglass cars, most electrical stuff has it's own
ground wire back to the battery not to chassis as chassis is only
spaceframe and difficult to connect to and probably not very well
connected to battery anyway.

So:

1) do I run an earth from the amp all the way back to the battery -ve
terminal

2) do I run it all the way back to battery area, but earth it near
where the battery is earthed onto chassis from alternator

3) do I run earth to some metal thing that is connected to the chassis
(like the petrol tank).

stu

In article ,
(powerlord) wrote:

Fitting an amp in the boot of my TVR tuscan (fibreglass body).

I'm unsure of how good an earth I am going to get trying to ground the
amp onto the petrol tank (the only thing metal in the boot).

As with most fibreglass cars, most electrical stuff has it's own
ground wire back to the battery not to chassis as chassis is only
spaceframe and difficult to connect to and probably not very well
connected to battery anyway.

So:

1) do I run an earth from the amp all the way back to the battery -ve
terminal

2) do I run it all the way back to battery area, but earth it near
where the battery is earthed onto chassis from alternator

3) do I run earth to some metal thing that is connected to the chassis
(like the petrol tank).

stu

Run it back to the battery. Make sure you don't have a sucky amp that
connects the RCA input shields to the (-) power line. You'll get such a
wicked ground loop that you might even burn traces off a circuit board.
The amp needs differential inputs. Resistance between the RCA shields
and (-) power should be at least 15 Ohms, but hopefully over 220 Ohms.
If not, you'll need an audio isolation transformer.

Ground it to the tank? That's just dumb.