Reminds me of a Bristow 206 that landed at Sywell for fuel and wouldn't start.
At the request of the pilot I went for a look and it was apparent that the start relay was operating but the starter gene wasn't turning.
So being short on ideas I gave it a wack with a nylon hammer while the pilot held the start switch down. A huge shower of sparks resulted, I fell off the steps, but the engine started.
Problem now was no output from the gene.
The pilot decided to call for advice and left the aircraft padding next to the pumps while he went off to find a phone.
We all went and hid at the far end of the hangar.