Weird AC problem in 01 V70 XC

My 2001 V70 XC has started occasionally blowing cold air in the winter
when the outside temperature is below freezing. It can be stopped by
turning the 2 temp knobs up to the red line and turning the fan down.
It then usually goes away and starts working normally.

I have the automatic climate control system. It normally works just
fine in auto with both temp knobs set to 70 to 72F. It starts blowing
cold air on very cold days after everything has worked just fine. I
notice very cold air coming out of the dash AC vents where no air
normally comes out at all in winter.

Pressing the AC OFF button doesn't solve the problem. Turning up the
temp knobs doesn't seem to help until they get up to the red lines.
Then, to keep the fan from revving way up, I have to turn the fan down.
Soon after that I can eventually turn the knobs back down and use the
auto position.

I am afraid that if I take it in for service, they will never experience
the problem since it seldom happens. Has anyone observed this problem
and found the cause?

 

Are you sure the AC is coming on or is it just letting cold ambient air in?

 

I keep the AC always on in winter, but shutting it off doesn't help. It
keeps letting cold ambient air in since turning the AC switch off
doesn't change anything. In the winter I have to keep the recirculate
button in the off position since otherwise the windows will fog up bad.
That doesn't seem to be a problem. We have done that for 8 years.

The two problems seem to be:

it starts blowing air out the wrong vents on very cold days in winter,

it starts blowing cold air.

It doesn't seem to be a broken part since it only occurs sporadically.

It is some kind of a malfunction that goes away if I turn the
temperature selectors up to the red lines for a while.

It is going into the same state it would in the summer when it wants to
cool the car. It is sending cold air out the AC vents rather than warm
air out the defrost and floor vents. The problem is that it is in the
20's outside and just comfortable in the car before this happens.

Maybe a computer reset would help, I have no idea.

We did have a dead battery caused by leaving the parking lights on
overnight, so maybe the computer needs to be reprogrammed.

 

My 04 v70 blows cold air from the centre vent, but warm air from the
window side vent in cold weather. This also clears if I turn both temp
controls up for a while.

Dave

 

This may come as a late reply but here goes. (and it may not be totally on
point) My heater whole climate control system seemed to be out of whack and
I ignored it because we live in a fairly moderate climate and it wasn't of
great significance. I ignores my water temperature guage even though it hung
arount the 1/4 mark and the heater didn't work worth a toot. Finally I got a
"check engine" light, took it in and it indicated a faulty heat sensor. $300
later with 2 sensors replaced and everything is great. I know your problem
sounds much more complex, but thought I would contribute for what it is
worth.

Regards, Gerry

--
Gerry and/or Marilyn Pyper
102 Dogwood Lane
Salt Spring Island, BC
250.537.5756

 

Thanks Gerry. Mine may be a sensor on its way out. The problem is
intermittent, but is happening more often. Now I mostly run the climate
control like a manual system with the temp dials on max and the fan on
minimum. When have it in for state inspection or 130,000 mile service,
I will have it checked.