I got tired of having to turn it on and off on the field, so i installed a pressure switch.
UPDATE: now a look at what i did.
I removed a plug and so broke the circuit, then soldered the pressure switch where the plug was.
Above the on/off switch was a clear plastic slug that had no real purpose. I removed it and threaded the cord through the hole where it used to be.
The first thing is the clear plastic slug. The second is the plug i took out of the circuit.