Hello Steve. Sorry I responded so late. so on your light bar you will have a cord sometimes their really short and that can be a problem but if you have a fair length of wire you should be good. any ways usually there will be a thicker black wire with that you would connect to the negative side. then there are usually smaller wires that are colorful which would be on the positive side. if you have a strobe or LED light bar MAKE SURE NOT TO REVERSE THE WIRES it will cause the fuses to blow. this is what happened with my strobe light bar but I haven't done it with LED. if you reverse polarity halogen light bars they will usually rotate the opposite direction and be dimmer. for the most part its not to big of a deal if you do that to a halogen but its not smart to do that in the first place.