I 'm helping out a friend with 9650. Does anyone know where the low pressure switch is located?

He bought this tractor not too long ago, and some one has replaced the compressor with an aftermarket one of some sort. 

I'm use to A6 on Deere, with the press switch on the tail of the compressor. this just has a hot wire going in behind the clutch with ground coming back out and attaching to casting. Maybe the switch is in under there, if it is then it ruled out, because I can apply 12v from battery to the hot wire and clutch with engage.

I've ruled out the hi press sw, fuse and thermostat, it has tobe either in the wiring or the low press sw.

Anyone got any thoughts?

Thanks 

Tim