2005 Club Car DS 48V headlight problem, voltage reducer bad?

[spuds]

Have a 2005 Club Car DS that sat for about 6 months. Came with headlight kit installed from dealer (we bought it 10 years ago). 48V car.

Got it ready to sell, got a good offer, and discovered headlights aren't working.

Have 50.4V across battery pack (not connected to charger), brand new batteries.

Reading 8.3V at headlight switch.

Reading 50.4V across voltage reducer input (+) and (-)

Reading 8.3V at OEM (p/n 15950) voltage reducer (+) output to frame, 0 V across reducer (+) and (-)

Applied 1 battery's voltage to headlight wiring (pulled wires from reducer input, so current is running through wiring harness including fuse), headlights and tail lights come on fine.

Are we looking at a voltage reducer problem? If so, recommendations for replacement model? If not, what should we be checking?

Thanks,

Michelle