So if I’m following you right, (ignoring the switch for the moment) you shoud have a pair of wires leading from the power supply, and another pair of wires going out to the equipment or device that you are trying to remotely control. Now, your supply pair (the “line” side of the switch) should connect to the switch as follows: + to the red wire on the switch – to either black wire on the switch Next, your ouput pair (the “load” side of the switch) should connect to the switch: + to the white wire on the switch – to the remaining black wire on the switch Depending on how you had it connected the first time, the switch very well could have been damaged after power was applied. But not necessarily. Try using a cigarette lighter adapter and cord plugged into your car to test (the AA idea seems a little sketchy) after the switch has been wired in the manner above (disconnect your 7v device first and use a voltage tester to verify). If it works, try connecting your 7v supply and 7v device again. If it doesn’t work, then 7v is not enough to operate the relay. P.S. Forgive me for asking, but are there batteries in the remote? :)