Why is my heater screaming, sounding like something is stuck or fan is quitting? on 1990 Volvo 740

Problem started a year or more ago and was fairly intermittent, but is worsening. Lately I notice the heat does not blow out as forcefully when the heater is screaming. Could it be the intake air vent for the heater is clogged and if so, where is this located and how do I clean it out? Or is it the heater blower/fan itself?

by in Mountlake Terrace, WA on December 03, 2011
2 answers 1 comment
ANSWER by , December 03, 2011
You need to replace the blower motor.
COMMENT by , December 03, 2011
Thank you. I appreciate your advice.
ANSWER by , December 04, 2011
Take down the fan blower first and make sure rodents have not built a nest in the air ducting, check too that the cabin air filter is not totally restricted and blocked but this may not be applicable to an older Volvo.