Took me nearly all day, but looking back I started at the wrong end.
First I put a voltmeter on the solenoid wire and hit the start with the key.
Volts dropped to zero.
Next, left key on and shorted out the start solenoid. Engine started.
Did that a couple of times to be sure.
Next, found the start relay. Book says its the black plug in LH footwell.
Its not , its the yellow plug and relay going by the wire colour. (mid 93)
Pulled the relay and shorted the brown to Rw with key on. It started.
Next was the start switch. Pulled off the covers and held the voltmeter probe to the white wire ( IP solenoid) while turning the key.
It started as if normal.
Took the probe off, turned the key. No start.
Repeated that a couple of times to be sure , then noticed some movement in the block that the wires connect to. The crimp was a little loose.
Left the probe off and just pressed on the end with finger.
It started as if normal.
Repeated that a few times and all good. So that was the problem all the time.
I can either leave the covers off and press with my finger each time I start it or find a way to tighten the crimp or hold it with a hose clamp etc.

Long winded I know but may help someone

Keith