No AC and no heat

[mike_57]

Hello, I just picked up a 2002 3.0 with a manual. The AC wasn’t blowing cold so I figured it needed a recharge, went to do that put the pressures were fine so I didn’t add more, wasted $40 but that’s how it goes.
Then yesterday morning it was cold enough to turn on the heat.. and that didn’t work. Felt like it was just blowing the outside air into the car.
I ran the self diag on the climate control and that didn’t give me any codes, just a glitched out screen when it was done.
Found out the dccv is a problem on these so I checked that fuse, it’s good.

So in conclusion do you guys think I should start with replace the dccv or maybe should I try a heater core flush? Or should I start elsewhere?
Anyone else had the experience of neither heat or ac functioning at the same time?

 

[joegr]

1. That's not a "glitched out screen." If there are no current faults detected, the last self test lights up all the display segments so you can see if any of them are out.
2. Unplug the electrical connector to the DCCV. If you don't then get maximum heat on both sides, you have a coolant flow problem. It could be clogged heater cores (there are two circuits), but that is very rare. It could be a clogged DCCV, that's a little less rare, but still rare. There is a screen in the tee on the upper radiator hose that also could clog. Far more common would be that air in the system is preventing circulation. This air comes from micro cracks in the cooling system plastics. All of it, including the degas bottle needs to be replaced. The system needs to be filled and bleed exactly by the factory procedure, or use a vacuum fill tool.
3. Is the AC clutch engaging. Note that just looking at the low pressure gauge on that fill can tells you very little, and nothing at all if the clutch is not engaged.

 

[mike_57]

1. That's not a "glitched out screen." If there are no current faults detected, the last self test lights up all the display segments so you can see if any of them are out.
2. Unplug the electrical connector to the DCCV. If you don't then get maximum heat on both sides, you have a coolant flow problem. It could be clogged heater cores (there are two circuits), but that is very rare. It could be a clogged DCCV, that's a little less rare, but still rare. There is a screen in the tee on the upper radiator hose that also could clog. Far more common would be that air in the system is preventing circulation. This air comes from micro cracks in the cooling system plastics. All of it, including the degas bottle needs to be replaced. The system needs to be filled and bleed exactly by the factory procedure, or use a vacuum fill tool.
3. Is the AC clutch engaging. Note that just looking at the low pressure gauge on that fill can tells you very little, and nothing at all if the clutch is not engaged.

Awesome! Thank you for the direction, I’ll look into these things and see what it find

 

[mike_57]

Update
I unplugged the dccv and I have full heat again on both sides.
I can hear the AC clutch engage when I turn on the AC, so I believe that is working properly.
So will the DCCV only fix the heat issue, or does that also control the AC?

 

[joegr]

The DCCV controls temperature by adding heat. If you need 70 degree air out, the AC cools it to 50 degrees and the heater core heats that to 70 degrees.

 

[04_Sport_LS]

That way it takes the moisture out of the passenger compartment.