Okay, just got off the phone with Frank and he also ended up replacing his alternator. Fortunately he had an extended warranty and was only popped $100 for the deductible. The dealer quoted the alternator replacement at $716. YIKE!!! They gave him a little grief about the mud as they said it wasn't the water that shorted the VReg but the build-up of clay. Knowing how VRegs are typically sealed, I'm not buying that. Water is conductive. Period. If the VReg has a crack in its case moisture's gonna kill it. It probably wasn't bad enough to fail in typical rain conditions but certainly couldn't handle the submerging and pressure of the mud holes we plowed through.
I've got my fingers crossed for ya David! Let us know how it turns out!