Does a dead AC compressor also mean the heat won't work?

[Kane]

So my car is at a DMC vendor getting worked on. Before I took it there, I had burned out the AC Compressor. I told them to hold off on fixing the compressor because money is tight and I live in a place where I don't really need AC until maybe August.

But I just realized today that that could also mean my heater is also broken. Is the heater completely separate from the AC Compressor and my heat will actually still work? Or am I facing a long winter without heat unless I get it fixed?

[Josh]

They are entirely independent of one another.

[Jonathan]

They are entirely independent of one another.

I think Josh is right here. If you have your mode switch set to one of the heat options, it should be fine.

Which makes me wonder... don't newer vehicles also have some "air conditioning" even in the heat mode? And I mean the conditioning part of the air, i.e. the humidity or amount of moisture in it. I don't think our old cars can do that, but I guess I'm not sure. If you had an HVAC control that allowed you to select a particular mode that engaged the compressor, but still let you turn the temperature dial to the hot side, this might work. In the D though, I think if you put the mode selector in NORM, it only engages the compressor if you turn the temperature dial all the way to cold and get it to "click." And does the MX A/C setting trump the temperature dial? Is this right?

Interesting possibilities here...

[Exolis]

I think Josh is right here. If you have your mode switch set to one of the heat options, it should be fine.

Which makes me wonder... don't newer vehicles also have some "air conditioning" even in the heat mode? And I mean the conditioning part of the air, i.e. the humidity or amount of moisture in it. I don't think our old cars can do that, but I guess I'm not sure. If you had an HVAC control that allowed you to select a particular mode that engaged the compressor, but still let you turn the temperature dial to the hot side, this might work. In the D though, I think if you put the mode selector in NORM, it only engages the compressor if you turn the temperature dial all the way to cold and get it to "click." And does the MX A/C setting trump the temperature dial? Is this right?

Interesting possibilities here...

A/C is separate from both new and old vehicles. On newer vehicles, the A/C Compressor will come on when button is pushed or with some when the Defroster setting is turned on.

If I remember correctly, the DeLorean HVAC box is set up where you can have A/C Flow into the Heater exchange, however I think it will only come out through Front and Bottom vents and not the Windshield. You can turn heat on with the A/C on, the heat control is simply a door to direct air into the heat exchange. Max A/C is just the setting to recirculate the air inside the vehicle instead of allowing air coming in from outside.

[DMCMW Dave]

A/C is separate from both new and old vehicles. On newer vehicles, the A/C Compressor will come on when button is pushed or with some when the Defroster setting is turned on.

If I remember correctly, the DeLorean HVAC box is set up where you can have A/C Flow into the Heater exchange, however I think it will only come out through Front and Bottom vents and not the Windshield. You can turn heat on with the A/C on, the heat control is simply a door to direct air into the heat exchange. Max A/C is just the setting to recirculate the air inside the vehicle instead of allowing air coming in from outside.

Max AC also turns off the hot water to the heater core.

[Jonathan]

A/C is separate from both new and old vehicles. On newer vehicles, the A/C Compressor will come on when button is pushed or with some when the Defroster setting is turned on.

If I remember correctly, the DeLorean HVAC box is set up where you can have A/C Flow into the Heater exchange, however I think it will only come out through Front and Bottom vents and not the Windshield. You can turn heat on with the A/C on, the heat control is simply a door to direct air into the heat exchange. Max A/C is just the setting to recirculate the air inside the vehicle instead of allowing air coming in from outside.


Max AC also turns off the hot water to the heater core.

Ok, neat.

So, theoretically, if your A/C is working perfectly and is blowing COLD... like frigid... then you would use the temperature dial to adjust how far open the heater core door is and this will blend hot air warmed up from the engine coolant system with the frigid cold air and give you the desired end temperature you want? Assuming you want it slightly warmer than frigid that is...

[DMCMW Dave]

Ok, neat.

So, theoretically, if your A/C is working perfectly and is blowing COLD... like frigid... then you would use the temperature dial to adjust how far open the heater core door is and this will blend hot air warmed up from the engine coolant system with the frigid cold air and give you the desired end temperature you want? Assuming you want it slightly warmer than frigid that is...

As long as you are set on normal AC and not MAX that is true.

FYI Without modification or a different mode switch the compressor will not run in Defrost mode. Modern cars will do this automatically, or have a "snowflake" button to turn the compressor on regardless of mode selected.

[Henrik]

… and as we all know, air conditioning does three things:
#1:it cools the air (duh)
#2: it dehumidifies the air (when the air gets cooled below its dew point, the moisture falls out of the air which is why you see water (condensate) dripping out of the evaporator onto the ground and
#3: it cleans the air (pollen etc. clings onto the wet surface of the evaporator).

So if anyone is wondering why the heck the compressor is needed in defrost mode, i.e. when it is cold outside, the answer is per #2 that it dehumidifies the heated air. In other words, when the heated, (now) dried air hits the cold windshield and its temp drops below its dew point there is no moisture that can fall out and cause the windshield to fog up.

Of course, the ambient air is naturally dry in winter time so it is not that critical to be able to run the compressor while in defrost mode, in my mind.

[DMC5180]

+1

The effect of dehumidifying the defrost air is most noticeable when defogging. It will clear the windshield almost instantly or with in 10 seconds in most cases.