hello, i own a 1999 v70 glt with 150000 miles. over the summer i noticed that the ac was not very cold. i didnt think much of it because the air coming from vents was a little colder than ambient temperature. i am a bit worried now in the beginning of winter because the heat is not working well. the temperature gauge reads just under half of the range and the air coming from vents is not very warm. every now and then i notice the heat does get a little hotter and the guage reads in the middle. any ideas what this could be?

 

Hello, It sounds like one of your blend doors is stuck or broken. Get it to where the air is at it's warmest and try to make it cold by turning the temperature **** down. Is it an ACC (Automatic Climate Control) or regular A/C? Either way, see if you can make it blow cold, outside air (w/o the AC compressor on). I think dashboard HVAC is covered in the Haynes manual.
At the moment my malfunctioning thermostat has my temperature guage foundering around 1/4 range but the air is comfortably hot. T-stats malfunction on the cold side, I've read. If the thermostat has begun to act inconsistantly, change it. It'll be a perfect time to change your coolant, if necessary.
Also, come next Summer, turn your A/C on immediately after starting your car (before the coolant warms up) to get a handle on how weak your A/C is. At 150K a '99 might have a leaky exaperator. They say to turn the compressor off a mile or two before reaching your destination so the fan can blow the thing dry. I say; why do they make it out of cheap aluminum in the first place?
Kira