[MDBones]

Started the Jeep after work to let it warm up while having a smoke. Turned the HVAC on auto. Usually by the time I finish my smoke the system is blowing warm air, even in this extreme cold. Tonight it wasn't blowing at all.

I drove almost all the way through town... nothing coming out. Vehicle was at normal operating temp and the display was looking normal. LOL... this is not a good thing in sub-zero weather! At least the heated seats and steering worked.

I switched to manual HVAC control. Went through all the vent settings, manually ran the fan speed up and down from 0 to 6. Tried the windshield defroster. Shut the HVAC off, waited a few moments and turned it back on 4 times. No air coming out of any vent. Everything appeared normal on the display while doing this.

I turned around and drove back to the dealer so they could see this. When I got there I decided to shut everything off then stop and restart the engine. Turned the HVAC back on auto and here comes the fan as if nothing happened. Everything worked normally. Again with the electrical gremlins. Dealer said to let them know if it happens again and they'll set up a service appointment.

I had something similar to this happen a few weeks ago on a cold morning. I suspected that it may have had something to do with turning the HVAC on before the U-Connect display came up fully... it drags a little on really cold mornings. Merely turning the HVAC off-on brought the fan up so I didn't think about it further. I'm sure I let the display come all the way up tonight before turning the HVAC on... maybe I didn't.

The dealership manager told me something interesting though. He said that the driver's door is kind of like the "master switch" for the entire vehicle. He said that with the vehicle turned off that opening, shutting and locking the driver's door, then unlocking and opening it actually resets the electrical system, or parts of it... kind of like booting a computer.

I guess if the gremlins return I'll give it a try. In tonight's case, stopping and restarting the vehicle cleared the problem.

It'll be interesting to see if a TSB appears for this or if it's something else related to the loose ground recall.

 

[onebluemcm]

Well, glad you got it working with a shut down and restart. Sounds eerily like a PC with Windows......

I think ours have been just left in the auto mode since the day we picked it up. I may have once or twice or twice fiddled with the manual settings, but not much more than that. In older cars I used to shut everything off when I parked it - AC, radio, the works. Anymore, I just leave everything on. So maybe we have the gremlins too, but just don't know it.

Interesting for sure what the dealer said about the drivers side door. I believe it. And across brands too. Our '13 Focus Titanium is definitely that way.

 

[therobertbrooks]

Car are as much computer as machine these days.. When you have a glitch you restart the computer and 90% of your problems are fixed.. it would make sense that new cars are very similar.

I leave my JGC in auto all the time and sometimes it blows and sometimes it doesn't.. I just assume the temp is correct. But I live in florida so the temp is quite mild this time of year. I will have to keep an eye on it.

 

[MDBones]

I haven't had any more issues with it in the last few days.

In cold weather, when you set the HVAC to auto the fan generally doesn't come on for a couple of minutes until the engine warms a little so it's not blowing cold air. Fan speed will also vary to help maintain whatever temp you have set. That's all normal operation.

What I described above isn't... LOL.