I still have my original Univolt set-up in my 65 Caravel
. Yes,my pump and the fans run on about 19 volts AC. The shorepower 120VAC goes into a heavy step-down transformer and two wires emerge: 12VAC and 19VAC. I have 2 switches to throw to go from shore power to battery - one for each voltage feed. The original pump and fans run equally well on 12VDC or 19VAC. I don't expect that your new pump will work on AC at all though. As another poster suggested, you can run it directly off the battery. I can't because my AC Univolt set-up doesn't charge the battery. The Caravel
didn't get a rectifier to make DC out of the AC circuit.
Anyway, I like the Univolt transformer hum. OK I lied there, eventually I will change to Intellipower.