Took a nice cool drive earlier today on a windy road, AC nice and cool. Only symptoms were the AC clutch would kick out after idling at a light and then hitting the throttle to get rolling. I've seen that many times, the freon must be a tad low, the rev up bounces the pressure off the low switch. 30 hot seconds later the AC is back on, if you're rolling and getting some air over the condenser.

So this evening I went to add a bit of freon. AC clutch kicks in, I open up the gauges, and rev a bit to suck some freon on the low side. Click! AC clutch kicks out, never to kick in again. Nothing. I'm thinking the pressure switch has gone south. Gotta pull the bumper, discharge and recharge the system but not terribly painful. $20 part. Just frustrating...............

I'm wondering, is there a history of failure with the Nissan AC pressure switches?

 

Crickets..............

 

For what it's worth, I've always thought that AC work is best left to specialists. R134a kits from Autozone are garbage and can result in damage to your AC system because they can mess with the oil volumes. It's cheap enough to have a shop do a flush, vacuum and refill by a certified tech. If it's not holding a vacuum, then would be the time to add some UV dye to see if the problem is in the lines and isn't a mechanical issue.

As for the pressure switch failing, I haven't seen any issue reports on those, though they could be buried in some old thread. Do a search and see what you come up with.

All I know is that I've had my 350Z since new and the AC has always been terrible. I had it checked twice under warranty and both times they told me it was within spec. Yeesh.

 

Well, I was asking about the pressure switch just because I'm new to the 350Z and was wondering if it is one of those typical Nissan "little irritations". I consider myself "almost" an AC expert - I would never have a shop work on my AC, most don't know anything about it. Not had good luck with "certified" techs, at least those I've found. Nobody cares about my car like I do...... FWIW, the 350Z is 134A from the factory, no need for a conversion kit. Gotta go back to around 1994,5, or 6 to get the R12 cars.

I ordered the pressure switch already, because I'll have to remove the bumper just to test it anyway. Once I'm in there, I'll be ready if that's the problem. I'm 60% sure that's it, or else the clutch coil died instantly, and that looks like a real pain to get the AC compressor out. Hope that isn't it!!!!!

 

Just hardwire the clutch to see if it goes off and on..

 

Once I pull the bumper off, I'll start with jumping the pressure switch and then move to the clutch. There is so little room to get in there I couldn't even see the harness for the clutch in order to test it.

FUN!!!! (not)

 

Welcome to the world of I wish I had small hands.

I was trained on AC systems and know how they work and lived through the whole Freon changeover, so I know how that went. Honestly, I'm glad the Ozone Hole isn't so big anymore. That said, most people don't have the equipment to properly dispose of the used R134a (unless they just want to dump it into the atmosphere; kind of like pouring used motor oil into a hole in the ground). R134a is safer than R12, but it's still not something I'd just want to empty into the air.

Also, your average shade tree mechanic isn't going to have the manifold and vacuum tool needed to do their own AC work. They think a $29 can of refrigerant from Autozone is going to make their lives great again, and 9 times out of 10, that's just not the case.

I suppose a lot about the quality of paid professional work is going to depend on where you live, but I'd hope that in a warm/humid weather climate area, you'd have at least a few decent techs out there who can do the job properly.

Either way, good luck and let us know how the new switch works.

 

Crickets because few of us have problems with AC? Hot as heck here, thanks God mine works.