Are there 2 alternators on an 03 Liberty, one for house and one for engine batteries? We seem to not be charging as we roll down the road. Gauges and Liberty book indicate we must have some issue with our " alternator". Since gauge for engine appears normal, I assume there must be 2 alternators. Just fired generator up to charge so they don't drop too low. Any ideas what we look for when we get home tomorrow? Thanks everyone. Deb