replaced the blower motor on my 1990 760turbo,motor was bad , now there is no air coming out of vents. any suggestions please
ps. replaced it with a motor from the wrecking yard. the fan switch works on all five settings. lo-high still no air thru vents.

Just a thought, is the fan motor connencted the right way round?
This is a brush type motor and will run backwards if the polarity is reversed.
Colin.

Is air coming out of the defroster vents? Vacuum is used to operate the servos on the ACC (Automatic Climate Control) system. If there is no vacuum the system defaulst to defrost. The Volvo engineers decided that if the system should fail, keeping the windows clear was the most important objective. Check the vacuum connections. If you have vacuum, reply to this post or message me and I will send you the trouble shooting guide for the ACC system.

Read you advise on the blower motor issue. I have a similar issue with blower motor working, but I only lose my air flow thru the vents in turbo boost mode. I'm guessing that is because it is creating positive pressure in the crankcase? Any adive would be appeciated. THanx

You have a vacum leak somewhere in the system. The heater system defaults to defrost with a loss of vacuum. There are sevaral places to check. See the 700/900 FAQ. The first place to check is the rubber cap on the unused nipple of the vacuum reservoir.

thank you for your reply, some air coming out of defrost, not full strenght, i will check vacumm,please senn ACC trouble guide