1990sl500 starting problem
 

1990 SL with 36k very clean miles have an electrical problem -- intermittent
When key is turned, idiot lights go on but no click from solenoid, no turn of starter. With headlights on and key turned they do not dim.
car sits and on its own, eventually, key will work.

took into dealer and spent $360 for towing and a $50 relay replacement. Dlr said wasn't sure it would fix problem as the car started working for them before isolating fault. Home two days later won't start. 15 minutes pass and it works again.

Dlr said it could be wiring harness ($1500+) or other very expensive part and doesn't want to hunt and peck on our wallet.