HVAC - lower the power drain or disable the heater ?

[Windydrew]

So back on topic and reviving an old topic, I confirmed this morning that using the FORscan commands on a computer will force the heater to 0 even after disconnecting. I can now set my HVAC to 70°F and it doesn't burn the 5kw that it usually does when I turn it on in the mornings. It's 67 outside and even having it set to 70 with the AC off, it is using almost no power. Now I have to make sure I turn it back on before it gets cool out this fall, but I'll leave it off all summer! I'll make a new topic later with pictures and how-to. Thanks

[Windydrew]

Just back in the car after hitting the gym and when I turned on the car, it was pulling 5kw+ again. So it's not permanent, only for that drive cycle before turning the car off and back on. That's unfortunate.

[amped]

There should be a high voltage fuse for the PTC heater. I wonder if anyone has experimented with removing it?

The FFE probably has a temp sensor like the one mentioned in the Leaf forum so I imagine methods 1 and 2 could be adapted if the appropriate wire/connector can be identified. Method 3 seems like it would require a lot more info to implement properly.

Wouldn't it be easy enough to just use manual control and switch the heat on or off periodically - keep the fan going in recirc (why does this car hate recirculation so much?!?!?) to suck every last bit of heat into the cabin. I often have to resort to a similar approach with the AC to prevent the F%$&*@! heater from coming on during the spring to fall in my hot, humid climate.

[triangles]

There should be a high voltage fuse for the PTC heater. I wonder if anyone has experimented with removing it?

According to the wiring diagrams it's 40A and it appears to be in the TCM. If I can locate the fuse I'll remove it I'm guessing its under the cover of the TCM. Of course taking all HV precautions.

The other idea I had was simply unplugging the HV cable to the heater. However I'd have to get a junk cord to modify as I wouldn't want to leave the plug on the end of the wire or the socket on the heater exposed to the elements.

I was kind of hoping this would be simple like cutting a control wire and inserting a switch or using FORScan or FoCCCus to enable/disable in software...

[DianeMQy]

Thanks for your interesting thoughts. I'm waiting for the photos. Indeed, it is a difficult job to realize such ideas. I'm HVAC technician, I finished HVAC Vista College https://www.hvacschools411.com/certification/ some years ago. And I know from my own how difficult is it to avoid overheating and uniform temperature distribution. The main thing is correctly to install, clean, maintain and repair heating and cooling components. Such systems need good care. You must be meticulous and responsible to avoid workplace hazards. So it is really a responsible business.

[Heima]

Considering that post was made in 2017, I don't think they will be posting pictures anytime soon.

[Anti_Climax]

Based on how difficult it is to get into the TCM, you'd be best off splicing a switch into the heater or just disconnecting it entirely when not needed.



You could also tap something like a CANDue into your CAN bus and have it resend your preferred heater command each time the car starts. Now that I have the Arduino in place for CHAdeMO, I've been thinking of having it modify a few things like this - watch for the recirc to turn off and turn it right back on.

I might add a new control for the seat heaters (I don't think they are controlled on CAN) so they don't turn on unless the temp is below a certain threshold or add a stand-alone interlock circuit that turns them on/off with a momentary contact switch - but defaults them to off when the car starts locally and on when it's started remote and plugged in.

Maybe something that would mute the stereo when it can't connect to my Bluetooth or when I disconnect from USB audio...