No starter condition

[Phil Payne]

This is now happening on BOTH of my cars - an MB ur-quattro (very similar to an MC-1) and a
100 turbo Avant with an MC-2 engine.

Turn the key, and everything lights up but the starter doesn't fire.  No click even from the
solenoid.  Batteries are fine.

I've previously found two causes for this condition.  The first I saw was corrosion of the
short braided grounding strap between the starter solenoid and the casing - that was about
eight years ago on the MB.  The second is a failure of the ignition key switch - I've long
assumed this is caused by heavily-loaded keyrings.

We can exclude immobilisers - neither car has one.

Before I commit a weekend (I need to put new brushes into the alternator regulator anyway) has
anyone seen other causes of this phenomenon?

--
  Phil Payne
  http://www.isham-research.com
  +44 7785 302 803
  +49 173 6242039