S40 2001 airconditioning/heater/defroster won't work

[revolvo]

For the last couple of weeks, my s40's heating system was a bit wonky - it would be running pretty high - lots of heat blowing at me and even when I tried to turn the heat off, it would only decrease slightly. After one of these episodes I turned off the car. Then I turned it on and.....nothing. Now there is no heat, no A/C, no defroster. There is a faint whirring when I flip my switch around from defrost to the other vents, but it is as if the whole fan mechanism is blown. Has anyone else had problems like this with their Volvo? It seems like it might be a simple fuse issue, but I don't know what made the fan run so aberrantly. Any ideas before I take it in to the Volvo dealer would be greatly appreciated.

Thanks!

[MadeInJapan]

Welcome to MVS.
There are #11 (11A and 11B) relays that control the climate control unit. One is found in the relay box, just below and to the left of your steering wheel and the other in the large relay box under you hood (up near the windshield on the driver's side). You can check the ohms between two pins in socket for your relay in the cabin by following the instructions below:

S40 Relay Check.jpg (39.66 KiB) Viewed 1382 times

However, your system is very sophisticated and stores Volvo specific codes that will pin point the exact problem with your system. I looked through VADIS and to problem shoot your system, it might take me a whole day and still I might not have found the problem. Let me suggest that you go ahead and take your car to a dealer you trust and who's reputable or an independent shop that has the VIDA equipment to read your codes. Unless there is more information to go on, it is going to be very difficult for me to give you enough direction to really be of much help.

Oh, heck- I'm sending you all of the A/C system component specifications file. If you really want to tackle this yourself, it will show you what to check (including what I already posted above). Still I say, you're best bet is to take it to someone with the specific scan tool:

S40 components check.pdf

(200.77 KiB) Downloaded 505 times

Good luck, and please post back to let us know how things went and what you did.