i'm putting in a heating o2 sensor in my 90 civic and need to hook the heater to a switch power source so the heater won't stay on all the time. where's a good switched power supply to hook it to in the engine bay?

 

i hooked a freind of mines fan up to his negative side coil wire... Works fine, but I wired mine to one of the wires on the drivers side harness, just go get a test lights and check it out..

 

I connected mine on the driverside harness too...yellow wire for switched power, i think...