Afternoon peeps,

Not sure if this is the right place to post this, so mods please feel free to re-locate if not.

Strange query, but basically I have been asked to help wire up a head unit and speakers to,,,wait for it,,, a 1980's Harley Davidson/AM Golf Buggy. Don't ask !

I have an idea how to do the speakers etc, and how to wire the main power up directly to the battery (with a suitable wire and fuse etc) and the aeriel, but I'm not sure of the best way to safely and securely earth the actual head unit ? It doesnt have a wiring harness/connector block and just has the individual wires coming our of the back. The Power Supply description is '12 Volts DC Negative Ground' which I assume is pretty standard, and the wiring diagram shows the black earth wire coming out of the back of the head unit, and connecting via two branches to the negative point on the battery and to a separate 'Negative Ground'. Is this just supposed to be grounded to the metal bodywork ?

The buggy is mainly fibreglass I believe and the only metal structures seem to be the chassis sub-frame or the engine block. Any suggestions on how to do this as safely as possible, or does anyone have a link to a basic guide on direct installation. {The google ones all seem to refer to using wiring adapters and harnesses for cars etc)

May seem like a noob question so apologies in advance, i seem to have been given the job as I fittted a couple of stereos to original minis over 10 years ago, but they were easy and just got grounded to the bulk heads etc. And I havent done any since.

Anyway, any help or pointers would be greatly appreciated. (Thanks in advance)

Just run a wire back to the battery negative terminal if its fibreglass bodied. By connecting to the bodyshell (a metal one) your effectively connecting back to the battery anyway as the negative terminal on the battery is connected to the chassis. The concept is partly a way of saving wiring, if every earth cable had to return to the battery then more wire is needed hence more cost involved.

Excellent, thank you very much for the speedy response.

Presumably the earth wire doesnt need to be any particular gauge, just be of reasonable condition and thickness ?

Also, can I hard wire in the yellow 12v memory back up wire to the +power on the battery as well as the main red power wire, as there is no ignition to speak of to wire this through. Not even sure if this will be required as I don't think stored presets etc are going to be required, just the facility to play cd's mainly.

The last power related wire is blue and is the for the power antenna, and as we're not putting in an amp I assume thsi can be totally ignored.

Cheers again.