Best practice guides

Disconnecting the battery

When disconnecting the battery before commencing work on the car, you should disconnect the negative, black lead first, here's why:



The answer to most electrical problems is to start by checking the earths in the car. The battery is usually connected to the engine by an earthing strap and the engine is separately connected to the car chassis by a further strap.


Some notes on welding, brazing, bronze welding and electric welding by Chris Flavell