'79 300sd starting problem when warmed up
 

After initially starting the car and driving around for a short while (15-20 minutes), shutting the car off, then trying to start again, all that happens is a faint click after turning the key. So far, I've been lucky enough to have the car start after repeated attempts (usually in the 10-15 attempt range). I'm worried that I will be left stranded one of these days. Any thoughts or advice would be much appreciated.
Thanks,
AP

Try jumping the terminals at the junction box. ON your model I think it's under the battery tray.