Tech Tip From the Hutton Communications July Dealer Newsletter

The Grounds for Reliability

There is some conjecture as to how automotive electronics should be grounded. Some say anywhere on the chassis, others say a common point and still others will tell you the negative terminal of the battery. If the installation is a temporary one, with the radio plugged into the cigarette lighter and using a mag-rnount, it doesn't really matter.

However, when you get into permanent installations, particularly those involving mobile data or outboard signalling options, it is very important to ground all of your communication apparatus to one point - the negative terminal of your battery. This is the best way to ensure that the least noise possible is induced onto the power leads from accessories in the car. It also insures that there will be a minimum amount of voltage difference to each device (radio, display/status bar & modem).

We all know a fuse should be placed on the positive lead as close to the source (battery) as possible, but should a fuse be put on the negative lead too? It is never a bad idea to do this but in reality if the primary connection on the battery for the car’s starter is a good one, and the radio's lead is attached to it, it really isn't necessary. It is also to protect users from any danger of fire if the installation is less than perfect - which is occasionally an issue with hobbyist & consumer grade mobile equipment.