Hi there,
When I turn the key left, the engine doesn't stop and the fuel and temp guages stay on. Does that sounds like the ignition switch? If I disconnect the cluster it makes no difference . Strange to me. Any ideas please?

you're going to have to take it apart to find out.

just had an 81 300d that wouldn't crank nor return from crank to run. pulled ignition switch to test and found metal bits on the lock side of the switch. screwdrivr ok'd the ignition switch. pulled lock cylinder to check and it was intact. the COLUMN lock had broken and that what works the ignition switch when the key is turned. never knew. i've done lots of switches, lock cylinders and column locks over the years but never for this problem. hth, chuck.