sl168

I have a Sportster Relay that I've had for a few years now and I want to hardwire it into the car.I'm tired of doing the suction cup mount and adapter into the glovebox power routine.I ordered the Directed Electronics SIR-PVK1 professional vehicle install kit.The kit includes a power adapter,an FM direct audio relay that hooks into the antenna connection on the radio(the antenna then hooks into the relay),an inline fuse holder,plus the bracket and assorted wiring pieces.I've chosen my location for the mounting bracket and now I need to figure out where to hook up for power.The manual states"Test for a 12v circuit in the vehicle that is switched with the key.An accessory circuit is preferred and can be identified as a circuit that shows 12v when the key is turned on and drops to 0v when the vehicle cranks and then returns to 12v when the key falls back to the run position.the fuse holder should be attached to this circuit within 18 inches of the source".Then the power adapter connects to the fuse holder.What I'm wondering is if the cigarette lighter would be a suitable place to connect to.It's right there next to the radio and has a pair of wires connected by plugs going to it.Would I be able to tap into this wiring to get power,or do I need to find another location?If I can connect there,does anyone know which wire it is?I seem to recall one wire is white with a red stripe,the other I don't recall.I'd appreciate any help you can provide me.