Im not having any joy in getting the wiring diagram picture, so I will try and explain it to you!!
Fuse 47 in the CJB (glovebox) is the feed to the switch, there should be a 12 volt feed to the mirror switch on pin 6. Pin 4 on the switch should be an earth.
Pins 1,2,3,5&7 should be live or earth depending if you are pressing up/down, left or right
The wires then run from the switch through 2 connectors, (mirror multiplug & door loom multiplug) to the mirrors, so I would check you are getting lives/earths from the switch then at the mirrors and if none at one of the plugs, check back between the connectors to eliminate where the fault is
p.s. pin 4 on the mirror connector is live feed for the heated mirrors (fuse 50 in the CJB) and pin 5 at the mirror connector is earth
Hope that helps a bit ( if it makes sense

)