Having trouble with my heater. I can hear the blower, but I don't feel air coming out of the dash vents or the floor. I have the Climate Control system. After a while I get air coming out of the dash, but I feel very little coming out of the floor vents. The car does not get very warm inside even when I have the temp up to about 80. Not good when it less than 20 around here. What air I do get feels warm but not really hot. I was going to put a new Thermostat in, but the more I think about it, I doubt that is the problem. I'm pretty sure I have the 90 degree thermostat and it's only a year old. I was going to order an 87, but want to see what advise I get first.

 

What fault codes have you got?

 

Jim you may need to have the Dealer recalibrate the motors.
Sounds like one is out or bad.
Does the lights flash when you start the car?

 

Temp Gauge will tell whether thermostat is stuck open -- Engine would never reach operating temp.

In the Mitsubishi and Nissan world, I would check vacuum hose between master brake cylinder, thru firewall, and the heater/AC control module under the dash. In the Volvo world, I have no idea.

 

Hi Jim,

As long as the t-stat was OEM, I think it's ok and it'll show on the temp gauge as Robert has noted, unless the gauge itself is also shot, which is extremely unlikely. 3 degrees in Celsius is negligible, so the 87 wouldn't make much difference.

As M. Tech has noted, one of the damper motors might be getting tired. Haynes has an illustration for the motor locations. I am not sure how the coolant flow to the heater core is controlled on 850's ACC, as Haynes does not provide in-depth instructions for climate control system. This is just an assumption, but maybe the actuator (motor?)for water valve is at stuck partially-open position.

I can't think ofmuch else right now.


JPN

 

Temp gauge is right where it should be, but I ordered the 87 degree thermostat from Groton anyway. This morning I was getting pretty good air from the dash vents, but next to nothing from the floor. And it was 13 degrees outside. My legs never got warm, and usually Volvo's have great heaters that get warm real fast.

 

Concur with tech. Check the diverter motors. I don't know if they are electrically operated or vacuum assisted on the 850, but on an Acura of an acquaintenance, she had the same problem and it turned out to be a fuse to the motor was bad. So, if the motors are electrically operated, check for voltage or a bad fuse, otherwise.....

Glenn

 

When you try to change the air flow through the vents (by spining the dial) does the air change at all or is every setting not so great?
[align=left] [/align]

 

It changes some, but nothing great. It's mostly I can't get anything to come out at the floor vents, and it seems like the dash vents are very slow to open, but they eventually do open, but it still does not feel like they are open all the way.

Tech, I have not noticed the heater/AC lights flashing. I'll look for that the next time I start it though.

 

Hi Jim,

Sometimes the LED's don't flash, even there are codes stored, or maybe it's only my 850. The system is really fickle.

A worthwhile & cheap trial:
Locate the damper (diverter) motors, wiggle electrical connections, tap the motors lightly, etc... Or, disconnect the battery (may not be necessary), take the ACC panel out (The radio may have to come out first, just to get to the locking tabs on the sides of the ACC panel), disconnect the electrical connectors, blow dust from the box & connectors with a can of air duster. Reconnect everything back, let the engine idle with everything turned off for 5-10 min. for it to re-learn idle, if the battery was disconnected, and re-try the climate control to see if it's fixed itself.

Or, the universal way to fix anything: Hit the panel with a moderate force.

If this does not solve the problem, the dealer is waiting for your visit.....[8D]


JPN

 

Maybe before going to the stealership you should use these documents to see if you can diagnose it yourself.

http://www.matthewsvolvosite.com/dow.../Volvo_850.zip

There are 4 pdfs on thea/c system in there.

Regards

 

The lights do not flash. Something I noticed this morning while sitting at the ATM with the window open and it was 22 degrees outside, the blower started blowing hot air like crazy. Think it could have something to do with the temp sensor? Where is the temp sensor?

 

Hi Jim,

My 850 sometimes do not have flashing LED's, even if there are codes stored. I really don't know the logic behind this. This is a faulty self-diagnosis design. Or I should say, this is the beauty of electronics (once something goes wrong, no one can figure out the problem, including the person who designed it).

Anyway, according to Haynes, there are a few temp sensors:
1. Interior temp sensors, located behind the overhead handles, on each side (driver & pax). It looks like you may have to remove the handles to get to the sensors.
2. Air duct temp sensors, looks like they are located behind the dash, about where the radio is located at.

I would first check to see if there are codes stored, clear if there is, and see if the heater goes back to normal. If not, the following may do something.....

Cheap Fix Options:
1. With the heater at max temp setting, try cooling each sensor. You could perhaps use a can of air duster and hold it upside-down, so that the freezing liquid hits the sensor.

2. Disconnect the electrical connectors, and hook up your digital multimeter (if available) and set it at Ω mode. I believe those sensors are nothing more than thermistors, and if you try warming/cooling them, the Ω reading should change accordingly. If not, the sensor may be shot, though it is rare.

3. Simply unplug & plug the connectors, and see if it solves the problem. You could also try tapping it, hitting it, persuading it, convincing it, etc...

Pricey Fix Option:
1. Visit your local Volvo dealer[8D]. Tell them that 1,000 (the number can be modified to your preference) others are having the same problem on Volvoforum.com and request a "secret warranty" service.

If the heater responded with cold air entering at ATM, it may as well be one of the sensors, but I would still first try to see if there are codes, even if the LED's are not flashing. If you have OBD-I, the socket for ACC is B-1.

Good luck,


JPN

 

There is 2 sensors inside the car.
They are in the o-Sh** handles.