Is it the switch??
I've had a good search through this forum, and one or two others, and found only one case of a similar problem.
Over the last 2-3 months, I've had an intermittent problem with my 1996 S280. Originally, every now and then, when I turned the ignition key, all the indicator lights on the dash, apart from the SRS light which is as bright as normal, came on really faint, then gradually faded from view. Now, sometimes they don't come on at all. If I then turn the key as if to start the engine, she'll spin up as normal, but won't start.
I then remove the key, lock and unlock the car so that I get the green light in the rear view mirror, and re-try.
Sometimes this works, sometimes I have to do it 4-5 times. As soon as I get all the lights on the dash, at the usual brightness, I know that she'll start as normal.
The battery is brand new, so there's no problem there. Local independent garage suggested that it may be a problem with the sensor in the rear view mirror, but changing that made no difference. I figured it could be either the ignition switch or possibly the key-fob battery. Key batteries have been changed to no effect. Today I bought a new ignition switch, which I plan to fit next week. Any tips on fitting would be appreciated, as we don't have any manuals available in the UK.
If this doesn't work, has anyone got any ideas? I'm starting to get paranoid about driving too far in case she gives up the ghost completely.