I'm installing something and want to put a on/off switch (2 prong). Should I use the 12V positive wire or negative wire to put the on/off switch on; or it doesnt matter?

thanks

 

Technically, either way will work, although it's more common to put the switch in the positive power lead. The reason is that components often have more than one path to ground, so putting a switch in the "primary" ground wire might not completely isolate the accessory from ground.

When you're wiring everything up, don't forget the fuses where appropriate!

Scott

 

That way, everything will be at ground (0 volts) when the switch is off. The reason this is good is if there's a problem like a short, the switch will isolate the problem. If your switch is on the negative side, you turn it off and the short is still powered. While a fuse should take care of this, it depends where you put it!

Also, for things safety, it's good to stack them so you really need multiple failure modes to happen at the same time before you find your self in the *******!

Matt

 

Thanks for the replies.

By "stack them" -- do you mean put the on/off switch and then a fuse both on the positive?

So this is would be the plan: tap splice the car's positive -> wire -> fuse -> wire -> on/off sw -> wire -> shift light

 

Have fun!

Matt