there one for $30 shipped from suvlights (i think it still going on)
and there $20 from the shop in my area. the $30 one plugs into the stock harness and the $20 one has to cut off the stock harness and wired to the aftermrket one. which one is better? please help

 

what kind of harnesses are you refering to? Your best bet is to buy one that plugs into the factory harness, it is easier to do and there is less room for error. It also makes the car easier to return to stock condition should the need ever arise.

 

but im kind of afraid that something will happen to the battery. i have 3 wires running from it (amp, alarm, and foglights)now i will be adding another.is this a problem?