Running A/C in parked RV all summer

I'm in full agreement with J-D. Check your 30 amp contacts thoroughly and make very sure that they are very tight. A loose 30Amp contact soon heats up and darkens. Slowly over time, that causes an increase in resistance which causes heat which ruins the power head as it melts.

It may be even with tight connections, the amount of run time for your A/C in Yuma over the summer will ruin the head so might as well get a spare from Home Depot or Lowe's or your neighborhood Ace Hardware so you have it on hand. I always carried an extra and they came in handy.

I'd certainly check the power cord head every morning or late afternoon when it's cool enough to work on if necessary. About all you can do is wire brush the main contact on the head.

If voltage is OK, filters and drains clean, it's just wear on an appliance that's otherwise just an old "window shaker" room unit. A very long-lived machine. In addition to the other cautions mentioned, be sure your Plug and Receptacle are pristine. I doubt you have a 15000 unit on that Bengal with its size, but those put a lot of load on 30A receptacles. Just be sure connections are tight and the contacts are clean and bright. Can't really tune a 30A receptacle up, unless you take it all apart. Best to replace.

We were parked in Yuma over the winter and the sun was hot! We are now in N Mexico and the later afternoon sun shines on the windshield. Having the drapes pulled didn't help much. We ordered a roll of reflectix that was 4' X 10' from Amazon and put it in the windshield between the windshield and drapes. What a difference!!! I would get rolls and cover all of your windows. It will sure help the A/C and your electric bill. Our A/C runs 2-3 hours less per day now for comfortable inside temps.

The sun can fade things out (cover the windows), but I don't think that the heat will affect anything in the trailer.

so long as the voltage stays above 107 you will be fine. I hope your problems disappear soon.

I go to Parker and leave mine for 6 months at a time, when its really hot I leave the air on at around 90 degs when I am gone other than electric costs and wear and tear on the a/c there is no problem doing it.

Consider cutting Reflectix or something similar to cover the windows. It will help reflect the heat.
I don't see a problem running the A/C.

Nope.