airconditioning heater & fan not working
 

hi, i have an 850 GLT 2.5 20 valve, airconditioning is not working. the lights on the dash come on but the fan doesn't work. does it needs gas for the fan to operate and heater as the heater does not work neither? anyone think they can help. thanks. RAT

What lights on the dash come on?

If you are not getting any air circulation then the chances are good the blower motor has failed. There is only one blower motor and if it is bad it would be bad irregardless of AC or Heat selection. If the freon in an AC system is low there is a low pressure switch that prevents the AC compressor from engaging and damaging itself but the blower would still spin and blow air no matter if the compressor is working or not. The blower motor is located under the dash, behind the glove compartment. Best thing to do would be to find the connector for the power and use a 12 volt test light to make sure you have power going all the way to the motor. A new motor will run around 135 for the part. If you have the ignition on and the controls on and no power at the motor it could be the resistor.
If you're not sure of the diagnostics you can try here or Matthews Volvo Site.

I have put power to fan it works and power to Heat & AC Resistor but the big blue wire comeing out has no power and the controller that operates to the window, floor and vents you turn it around and nothing happens. just doesn't direct air anywhere.

What year is it?
When you first start it up do you get blinking lights from the two switches on the heat/AC control panel ?

yes 18 blinks when i first start it its a 94 glt

You need to pull the codes for the Heat & AC from under the hood by counting the blinking lights on that under hood panel and see what the system has to tell you.

I'm having a similar issue with my 95 850t. The problem is that when I try to pull the codes nothing happens. I follow the directions and insert the plug into B1, then turn the key on, but nothing happens...?

On the pdf instructions it shows an illustration indicating pressing the button 1x, 2x, then 4x. I don't see when/if this procedure should take place.

I'm also a little confused because most of the diagnostics I've done on this in the past seem to be fairly easy, but this one either requires a second person or you have to scramble back to the diag. unit after turning the key on. Just seems odd - but I am also a complete idiot from time to time; this may be one of those times.

Corbitt, will the self diag panel still work for the engine management system?

If it works for the other systems but not the heat/AC it might be the head itself that's gone bad. I'd wait for someone with a little more experience with them to wade in and give an opinion.

hi guys. i finally got hold of a heat & AC resistor. i put it in, now when you first turn the car on the fan will come on for about 3 secs and off again. i noticed when the car is running, if you pull the fuse out and back in, the air conditioner compressor would come on and back off again. i also pulled the dash out and noticed on the passenger side, 1 of the units that operates the vents to the dash board is missing. would that affect the other parts from working? also when you turn the car on it still has the 18 flashes on the REC and AC. the car seems to be an electrical nightmare. i'm loosing my hair over it.

when i find the issue i will let u all know

To initiate the DTC flashes: after switching on the ignition, press the button on self-diagnostic unit "A" for ~ 1 second: THEN the light will start its flashing routine.