KLPARKER - We have a 2005 Winnebago Vectra, which I believe is similar to your Itasca Horizon. The AC unit is in the basement on your RV? That's where ours is. Your starting amps on the AC seems very high. I have watched ours run, on the panel, and the amp load on AC compressor start is rarely higher than 38 amps even on very warm days. We can run both our AC compressors, the battery charging circuit, lights, refer on electric, etc., w/ our 7500 Onan (diesel) and have no problems at all. The generator just hums along happily making electricity.
I'm not sure you have necessarily solved your problem. Some of the other writers mentioned some things to look at to help determine if you have excessive resistance w/ wiring, connections, corrosion, etc. I highly recommend following up w/ those ideas as you should not have to make "adjustments" as you have been for basic systems to operate. Good luck and happy RVing!
