Nissan AC designed to NOT turn off?

I bought a new 2007 Nissan Xterra a couple months back and the AC won’t turn off unless I shut the entire truck down. Nissan told me the unit was designed like that on purpose. I’m not kidding.



I bought the truck in Naples, FL. On the drive home to Miami I realized the AC wouldn’t turn off. I shut the truck down at red light and that did the trick, but when I used the defrost, which automatically turns the AC on, the AC wouldn’t turn off again. It didn’t matter what mode was selected, whether the AC button was in the “on” or “off” position, the AC stayed on until I stopped the truck, shut the entire thing down and restarted.



I wasn’t happy. I figured this was infringing on my gas mileage and unnecessarily wearing the engine and the AC unit. I took it back to the dealer and they said it couldn’t be fixed. I thought this wrong. I called Nissan and at first they were baffled. They said, “Certainly it can be fixed.”



The next day they called back and said, “Mr. Zauner, you’ll be happy to know that your AC unit was designed that way to protect you from mildew that might build up on compressor manifold.”



It sounds to me like their AC unit was designed poorly and instead of fixing it Nissan invented an excuse. No one at the dealership mentioned this unique “feature” that protects the user against mildew nor was it advertised in any brochures.



Is there any reason to design a AC unit that won’t turn off?

That sounds like a load of bull to me. Many cars automatically turn on the AC when the defrost mode is selected, but you should be able to turn it off by pressing the AC button. You should try another dealership to see what they say.

Does this happen ONLY when on defrost??? Some manufacturers will have the AC on whenever you set it to defrost.

I called Nissan corporate. Explained the situation. They were baffled at first. “Nissan would design an AC unit that wouldn’t turn off.” But the next day they called and said, “We designed it like that.”

The service department at the dealer was right. He was shaking his head when he said the same thing.

Only on defrost. If you accidently trip the defrost mode, you’ll have to cut the car off at the ignition to turn the AC off.

Edit: “Nissan would NOT design an AC unit that…”