In line fuse on earth wires.....

hl

Thanks for that, it's all I probably need to know and makes sense.

2 minute job with the iron.

Regards

Hi hl please indulge me on this one. If the batt main earth is crook you are suggesting that the starting current will flow from the positive of the battery, somehow thru the body of the vehicle to the antenna earth and then back thru the radio set to the radio earth thereby cooking some components is that correct?

Yep, see posts below... It will either melt the antenna wire if the radio itself is not bolted to the chassis or cook something inside the radio as well.
Chances of it happening are not that great and in any case, I think it is actually a dopey idea to run the negative straight to the battery neg. A point on the chassis somewhere near the accessry earth is much better. I think the idea originated to reduce noise from the car electrics to get into the radio..

Cheers

Bonz

If the earth lead to your battery develops a significant resistance or completely fractures you will not have an effective earth connection to any of the electrical items in the vehicle installed by the manufacturer. All the other electrical items in the vehicle are connected directly to the body or chassis – not the earth cable from the the battery. If you install anything and wire its negative side back to the battery negative you may provide an alternative path to the defective battery earth lead.

A CB radio would be one of these devices. The CB radio probably won't be grounded where it is mounted, but the braid of the co-axial cable will be grounded at the antenna if the antenna is properly installed (there will be a few exceptions with special antennas.) When you first switch the ignition on, the co-axial cable and radio earth wire will cope in most cases. However when you attempt to start the motor your radio installation will be attempting to act like an earth return carrying the 3-600A of the starter motor current – this will create an instant brown smell. The radio will possibly be the only device as other things may be completely floating and thus not be effected.

PeterD