Right....did some wire tracing tonight but rain stopped play before I could try a fix.
Mini-facelift auto is wired up as follows:
F2----(Bk)----Cruise stalk common.
Cruise '0' (nc)-----(Bk/Rd)----Cruise brake (nc) ----(Bk/Bu)----Cruise pin A
F9---(Bk)---gearbox sel switch pin D.
Gear sel sw pin C (=D/1/2/3)---(Bk/Y)----Cruise pin D and Auto ECU pin 37
Simplest fix is to join Bk and BK/Y at the old gearbox selector switch connector or to splice into the Bk wire from F9 behind fusebox and connect to one side of clutch switch. Other side of clutch switch connect to Bk/Y wire on pin 37 of ECU.
Cruise should now work but I'm not very happy with this solution because the two primary paths for cruise 'Off' ('0' button and brake pedal) both rely on the same signal to the cruise box.
A safer approach is to cut both wires at the cruise brake switch and join the Bk/R to Bk/Bu. This sends the '0' button signal to A on the cruise box.
Now splice into a black wire from either F9 or F15 behind the fuse box, connect this through the clutch switch and cruise brake switch in series then join to the Bk/Y wire on pin 37 of the auto ECU connector. (Auto ECU is removed). This sends the brake/clutch signal to 'D' on the cruise box.
I will try this tomorrow and hopefully post up a complete set of wiring instructions for the auto-manual conversion.
Note, if you look at the 4 pin brake switch you will see two different colours for the contact blades, the copper ones are for the high current brake light circuit and are normally open contacts, the silver plated ones are for the low current cruise control circuits and are normally closed contacts. Dont cross them over when playing with the wiring, the silver contacts will burn-out instantly if asked to switch the brake lamp load.