Gary,
What I meant by "directly" is that according to my dash voltmeter I'm seeing full alternator voltages (14.xx volts) getting to my coach batteries' terminals. However, of course there may/better be some fuses in that path somewhere - either OEM Ford-installed uses or Winnebago-installed fuses - I certainly hope that path to the coach batteries is fused!
If you're only seeing around 5 amps max going into your RV's battary(ies) during low states of charge then something is not right somewhere.
How about your coach battery interconnect solenoid that hooks up the engine charging circuit to the coach batteries? It's contacts may be pretty bad from corrosion and/or oxidation creating resistance in the path to your batter(ies).
What voltages are you seeing on the coach batteries when the engine is running (you may have already mentioned this, but I didn't reread the thread)? As I said earlier, I monitor both coach battery bank voltage and current flow into/out of the bank from the driver's seat so I can tell what the alternator is, or is not, doing to them.
Also, my voltmeter on the dash does not see coach battery voltage right at the batteries' terminals. It monitors the coach's overall 12 volt circuit voltage a little ways from the battery bank ... so it reads a little lower voltage than what is actually on the coach's battery bank terminals ... but the voltmeter still shows 14.XX voltages, initially, from the alternator. What this approach buys my is - whenever I see full alternator voltages on the coach's 12 volt circuit when I start driving it means two things - the alternator/battery handshake is OK ... and I remembered to turn the coach battery bank's interconnect solenoid back on after refueling at a gas station, hence the refrigerator is back on and operating! I used to forget to turn this interconnect switch back on after refueling before I had a dash voltmerter to remind me.
For what it's worth, I suspect that you're not alone - I'll bet that a lot of motorhome RV owners with some time on their rigs no longer have a good clean handshake going on between their engine alternator and their coach battery banks.
