Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Keeping AC on while passenger waits in car

This site may earn commission on affiliate links.
On occasion, my front seat passenger will wait for me in the car while I run into the grocery store or something. However, ever with the key fob remaining in the car, the AC shuts off and seemingly can't be turned on via the touch screen.

If the passenger moves to the driver seat, it will work (evidently because of a weight sensor in the seat).

Is there some (probably obvious) way to allow a lone passenger to maintain control over the HVAC?
 
You can also engage the parking brake from the touch screen before getting out instead of putting it in park. This leaves the car "on".

Beware, however, that someone can jump in the driver's seat and drive the car in this mode so it might not be the safest way. Same goes for leaving the fob in the car.

I never thought about hitting the brake before exiting. Problem with that is that it might turn off after a short time if no butt is sensed in the seat.

It all comes down to the High-Voltage contactor in the battery. When the car is off, the contactor is off so the battery is disconnected. When you first open the door, you'll hear a clicking noise. That is the contactor. This needs to be connected in order for the AC to work. When you get out of your seat and close the door, the contactor closes (clunk sound) and the AC goes off. When you engage the parking brake via the touch screen, the contactor stays connected and the AC remains on. Some call this "camping mode" by the way.
 
As long as you touch the screen within a few seconds of when it goes black, the car will wake back up. IIRC, every 15 minutes it will try to go to sleep again, just touch it when it does. Stepping on the brake will keep the drive rail on, (no need to waste the extra power), but it too will turn off after 15 minutes. If you aren't plugged in, you can put the car in Neutral and set the parking brake which will force the drive rail to stay on. This will last about 6 hours before it goes to sleep too.

You can also just leave the door slightly cracked (first latch point) and the car will not shut off initially, nor will the alarm arm, which is what I do when leaving someone in the car.

(I also have a "camping" mode that I've added to my app that keeps in on indefinitely, even while charging)

The contactor will not open if there is a load (such as the A/C running), so there is no need to worry about that. If the car is awake, it will stay in support mode (contactor closed) even if the drive rail is off, as long as there is some HV load. (HVAC on) Of course, if the screen goes to sleep, it will shut off the HVAC unless someone has turned it on remotely.