[russell]

Yeah, it might be best (if it is legal) to run the ground wire from the compressor straight to ground on the breaker panel (not through the spike), then run the positive wire to the positive side of the spike. Then hook up the spike normally, and replace the regular fuse with the auto reset breaker and you are good to go. That way even the worst programming screw up couldnt possibly run the compressor backwards, the only way to make it run backwards would be to plug the battery in backwards. But dont do any of this unless someone (more knowledgeable than me) confirms that it would work and is legal.