After an eventful three day trip to Tennessee, we pulled into Camping World in Statesville, NC. I left the Barth running for 2 minutes. The dash air had been working beautifully all the way from Tennessee, about 6 hours. While I was in the store, the significant other decided that it was getting a little warm in the Barth, and pushed the "max air" button. Immediately, the system started to hiss, and within seconds, a loud 'pop' and a huge cloud of white stuff, both inside and outside the Barth. I thought it had broken a radiator hose. Tere immediately turned the a/c off. And we left it there to have some other work done. Any thoughts on what happened? That was the last event of the financially troublesome weekend. If anybody is interested, the rest of the story will be in the travels section

Well, it wasn't brain surgery. The hose connected to the dryer blew up. $537 for parts and labor and R12. They haven't figured out why it blew up when we pushed the "max air" button.

Got a email from a friend in Canada who had the same thing happen to him. It seems that the clutch in the fan was not working right and the condenser wasn't sufficiently cooling the freon, ergo higher pressures in the system, and a blown hose. It happened when the Barth was standing still and the fan was off. The fan had been working fine during the trip. Perhaps I should change the thermostat setting for the fan? Or maybe do something to get more air to blow across the condenser, or maybe turn the dash air off and use roof air on warm days, or what?

My a/c on the Barth, & my previous SOB, both have two thermostatically-controlled electric fans mounted in front of the condenser to provide additional cooling. They worked on the SOB. I've never heard them go on on the Barth, but I've not yet had any overheating problems either.

They're available in the after-market, and not hard to install. If you don't have them now, they might be helpful.

A Pee can benefit from a thermostatically controlled fan for several reasons. It will kick in in slow hot traffic, slow uphills, fighting your way into difficult boondock parking, and most importantly, it will run for a while after shutdown, preventing the dreaded heat soak. Heat soak cooks your starter, wiring and hoses.

It is an additional benefit to wire the fan to run whenever the air conditioner compressor clutch is activated, to help dissipate the added thermal loading on the condenser and radiator.

It will also make your kids smarter and your dog will mind.

Well, so far they haven't found anything except a bad hose. They replaced a valve in or near the evaporator and the hose and some other parts and ran it for a couple of hours on max air and everything is OK. But we are installing an electric fan that will kick in when the compressor comes on. The technician said that it would help and that most newer rigs have them. It's just money!!
Jim

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I'm by no means a Barth expert (having seen and fondled only two in my lifetime), but any engine-driven A/C should have high- and low-pressure cutout switches. These vary depending on model (my cheapo little Class C has one that's adjustable).

Even early A/C units had a one-time overpressure valve to prevent blowing the HP line.

BTW, conversion to R-134a isn't rocket science - evacuate the system, add the poly oil and refrigerant, and it's good to go.