My radio suppression relay (4 terminal 40a relay mounted on the coolant tank) stays engaged after engine shut-off, draining the battery if the car isn't used daily. I think it's because of a Clifford car alarm that is tied into the car's system and is a rat's nest that I don't want to mess with.

If the battery is disconnected even for a second, the radio suppression relay cuts out and does not re-engage even when the battery is re-connected until the engine is started, at which point it will stay closed until the battery is disconnected.

I am going to install a relay that only allows power to the relay coil IF the ignition is actually on (so I don't have to disconnect the battery all of the time), but don't know what wires go to the activation coil. My wiring diagram is miserably small, and I don't want to start cutting wires.

Does anyone know what color wires are connected to that relay ? There are only 4, and one is black. My guess would be that it's a ground, and would be my candidate to interrupt w/ the relay if no one has a key to the colors, but any help would be appreciated.

Thanks,
Bob