Originally Posted by
Joe_Lukeman
Why is it important to disconnect the negative cable of the battery rather than the positive cable? I installed a really heavy engine ground to the negative battery terminal and it is a bit more difficult for me to remove. The positive side removes really easily.
Number 1, it is safer to remove the NEG cable first (in a NEG ground vehicle) so that the tools used do not accidentally touch any metal (as in if you did the POS first). Number 2, IF you still have the working siren, it'll sound off as designed, thinking someone is trying to steal the car (cutting battery cables). Safety first for NEG ground vehicles, and siren screeching while your right next to it in the cowl, good reasons!
.