Not sure what kinda amps the wiper draws, but I'd think less than a set of lights would.
Probably best to use the power wire for the wiper to activate a solenoid and run a power wire for the lights to the battery.
Well, the rear wiper is hooked up to a 20 amp fuse. I was gonna start checking the wire gauges today to see what the max amperage i could send through them would be. Would it just be easier run new electrical back to the lights rather than messing around with the harness?