Thanks for the helpful replies guys, did some more investigating.today.
When I first tried a start, just got the fast flashing immobiser light.
Nice for it to happen in my garage rather than on a garage forecourt
like the last time.
After getting a screwdriver to remove the steering column cowl I tried the
key again .bloody thing started no problem.
Left running for 15 minutes to warm up then I went ahead and removed
the cowl (The coil is the same Ford unit that you show in the photo's Rog)
I tried the ignition again and got the dreaded fast flashing light.
Never been this regular before.
Battery fully charged, tried the coil in every position on the key barrel but
no joy.
Removed the under bonnet relay box cover to check that I was getting
full voltage, while there I pulled the relays and refitted them to make sure
they were seated properly.
Tried the ignition again and it worked no problem?
Couldn't get it to fail again today but determined that when working the coil
can be positioned anywhere on the barrel and it still detects the key.
The key is not detected by the immobiliser until turned, so you can't do the
detect and 20 second key turn that some models do.
Never had these problems with the hidden switch under the dash of my
spitfire 50 years ago.
