Would it be bad to hook a relay to be controlled by my ignition switch, so that when I turn the key, it is always on? Not sure what the duty cycle is on these. I was going to use a new, old style horn relay to control my compressor for air ride. I tried using the ignition feed on the fuse box, but it goes through one of the fuses in the box (10 or 15 amp), and will blow it from the draw. There is a 30 amp inline fuse for the compressor. My thought was to use the ignition feed to control the relay, which will put power to the system. But, I'm thinking it may overheat from always being "on" when the key is on. I want the compressor to be off when the key is off, to prevent it from running when I'm not in the car. The alternative would be to run the relay off a toggle switch, but I'd rather have it just work with the ignition. Thoughts?