Thanks I'll add that to the list. Likely candidates and the probable order I will work through them;

Inst cluster ground
lower engine wiring harness (alternator harness)
Ignition switch issue
Alternator


I have an alternator I can bring to a rebuild place, and I am pulling the ignitionn switch assembly from the parts car - I'll also see how to get at the lower harness on the parts car.

Also just had an issue on the last two drives where the temp gauge behaved strangely - after about 5 min they raise higher than usual in one case touching top bar in the other a bit below, then it almost instantly drops back to the normal range. Time to search more or possibly post another thread.

Paul