s-Max electric driver seat not working

[cnprior]

Hello,

My s-Max 2009, TDCI has electric front seats with memory settings, usually works great.

Came to it yesterday to put the seat forwards and no power from the forwards and backwards switch.

Recline and lumbar still work, passenger side works fine.......

Checked the fuses (in the boot),
Checked the runners for foreign objects
Stripped down switch and fiddled with it and cleaned it - but no movement.
Stripped down the passenger side and swapped that with the drivers side........operated lumbar and recline, but also sent the seat into a full recline.....whilst the switches look the same, they carry different part numbers and also are 'handed', if that makes sense.
Can't get the seat out of the car as I can't access the back bolts which go into the floor.

Next steps would be to check the front seat motor......image attached, do I check the motor for resistance to make sure it has not gone open circuit first?
Or do I apply a power to the 4 pin supply? If so which wires would you supply power to - there is purple, brown, red/white and blue/black.
I gather that seat motors are bi-directional with voltage one way making it spin clockwise and the other way anti-clockwise.......but there are 4 wires going to the forwards / backwards motor and I'm not sure which pair to supply voltage to - in order to check the motor.

Any other suggestions what to check in order to find the fault? I could go out and buy a new motor and switch, but I don't like throwing money at a problem without a diagnosis.......call me tight !!

Thanks in advance of help.

[cnprior]

with pictures...

[cnprior]

[Penelope Stopit]

Can't find a diagram

When in doubt, check which cables power the working passenger seat motor

You're correct, the direction of the motor is reversed by reversing the polarity