Fiesta 1.4 petrol Mk7 air con pump wires

[manwithtool]

I've been looking at getting my Fiesta's air con working.  Air con pressure is all fine.  I've checked the wiring and power is getting to the pump and the fan cuts in when air con is turned on.  But the clutch does not engage.  When I look at the pump the positive comes in via the two pin connector but goes to something in the pump before going to the clutch.  I assume this is some sort of sensor.  What ever it is the is power getting to it but not out of it.  Any idea what it is ? Just looks like a rubber bung with two wires going into it.  Held in by a clamp with one bolt.

Can I bypass this thing.sensor ? 

 

Any advice, I'm trying to avoid removing the pump and paying for a regass etc..I have a spare pump which works despite being off the car so what can this sensor thing do ? clearly not a low pressure sensor !

 

[manwithtool]

Just an update.  I still don;t know what the rubber bung/sensor thing is, but the replacement pump works so I assume it's nothing to do with pressure.  It might be a temp sensor ? 

 

Anyway, I bypassed it and it all works.  It's not been used on a long journey yet though !!

I had nothing to lose so figured I'd risk it ! clutch cuts in and out and air con works.....so far !