Diesel to 3rd Rail-- then back?

[bingdude]

I was on 2737, the Montauk branch token one-seater, about a year ago. There was a problem with the HEP (lights out in cars-- no AC). When we hit the 3rd rail at Babylon, some of the lights came back and part of the AC did. The crew was still using the PA to communicate instead of the ICS, and one of them said: "Tell 204 it all changes when we go to track power..." And all the lights went out when we left the 3rd rail on the Central.

Whatever the problem was got fixed when we left Hicksville. It feels like that train switches to 3rd rail whenever it's available.

[DutchRailnut]

sounds like engineer when he changed ends left mode switch in wrong(electric position)on trailing engine .
and that happend to be engine providing HEP.