PRR Electrification From Philadelphia To AC - Trains Magazine

D.Carleton

PRR wires crossed Delair and continued to Pavonia Yard. Traffic to Atlantic City was seasonal and never warranted electrification.

Not exactly correct.  The Pennsy electrified one of its two Camden to Atlantic City routes.  But it was done mostly with third rail and some overhead in certain towns.  The electrification survived the PRSL merger and was greatly reduced in 1948 and completely removed in 1949 when the state of New Jersey demanded that the wood bodied cars be removed from service.

You can see photos of some of the MUs on the South Jersey Rails Website