so what is the diff between having a relay or not for your 4x4 lights

 

the difference between fires and not.....

 

x2 !!!

 

well i do have a fuse so that will not happend

 

A relay allows you to use a switch on low voltage/current wiring, instead of the high current wiring. Also, it is easier to route smaller wires in the cab than the larger wires for the lights.

 

The other advantage of a relay is that you can locate the relay close to the battery and lights to minimize the amount of (heavy gauge) wire needed and to maximize voltage at the lights for best brightness. With a switch on the dash you'll be running a wire from the battery back through the firewall to the switch then back through the firewall to the lights then some sort of ground path that ends up back at the battery. With a relay you go from battery to relay to lights and then the same ground path. Also with the relay you have added flexibility in that you can wire the relay to only be able to turn on when say the headlights or parking lights are on (and turn off when those lights are turned off).