[Alan James]

Wife and I have a 2019 Bolt with the separate Heat and AC buttons. This time of year I like to run just “vent only” for fresh air, no heat no ac. So I turn it “on” with the main button, with both heat and a/c turned off. Yet the heater clearly starts to run and heat up the car if I turn the temp knob above ambient, and the ac kicks on if I turn it down... no matter what I do it seems I can’t get just pure outside air to flow through the cabin?

I am very mechanically inclined. I’ve built motors. I’ve literally sat in my garage playing with this and can verify the ac compressor runs when turning the knob down, and the resistive heater seems to kick on when turning it up. The air the comes out the vents absolutely changes temperature also.

The weird thing is it doesn’t use nearly the same amount of battery power as it would if I actually turn on heat or ac - the graph shows only a tiny sliver used for it. If I were to actually turn on heat or ac, the graph would show much higher %.

 

[PhilBo]

This may be your problem. From the owner's manual:
Auto Defog : The system will monitor high humidity inside the vehicle. When high humidity is detected, the climate control system may adjust to outside air supply and turn on the air conditioner or the heater. The fan speed may slightly increase to help prevent fogging. When high humidity is no longer detected, the system will return to
its prior operation. To turn Auto Defog off or on, see “Climate and Air Quality” under Vehicle Personalization -143.

 

[The Other Tom]

Same thing happened to me. Then I turned auto defog off and it hasn't happened since.

 

[Alan James]

Crap I didn’t even think of that! Thanks!

 

[cancan]

Wife and I have a 2019 Bolt with the separate Heat and AC buttons. This time of year I like to run just “vent only” for fresh air, no heat no ac. So I turn it “on” with the main button, with both heat and a/c turned off. Yet the heater clearly starts to run and heat up the car if I turn the temp knob above ambient, and the ac kicks on if I turn it down... no matter what I do it seems I can’t get just pure outside air to flow through the cabin?

I am very mechanically inclined. I’ve built motors. I’ve literally sat in my garage playing with this and can verify the ac compressor runs when turning the knob down, and the resistive heater seems to kick on when turning it up. The air the comes out the vents absolutely changes temperature also.

The weird thing is it doesn’t use nearly the same amount of battery power as it would if I actually turn on heat or ac - the graph shows only a tiny sliver used for it. If I were to actually turn on heat or ac, the graph would show much higher %.

After you select AC OFF and HEAT OFF, try selecting Outside Air and any manual air mode except straight up DEFROST (Air to Front Windshield). Then should be able to operate at any blower speed and get uncooled and unheated fresh outside air.