On your unit, the chassis alt charging system is DIRECT to the chassis batteries and does not go thru any Newmar installed equipment. You do have a Bi charge (BIRD) relay system, but that is for the Coach batteries charging from the chassis system. This BIRD has nothing to do with the chassis system charging the chassis batteries. Now, if you have a problem(short or open in the Coach battery charging system, that "may" affect the Alternator output, but not likely. There IS a voltage regulator on all Diesel Chassis engine charging systems, but it is Frtliner installed. Either in the Alternator or close too it. Sometimes on Diesel systems, the lower voltage for a few minutes is NORMAL as the engine glow plugs may still be activated for a few minutes. If the batteries are old/weak, then the lower voltage may be a sign of that, not your charging system. Start the Genset, and let the coach batteries be charging from your Inverter or Converter which ever you have. Then start the chassis engine and see if you get the same voltage drop and rise. Doug
