I have a 1997 960 with an erratic and sometimes intermittent operation in the blower motor. I "bench tested" the blower motor and it operated at full speed with no problems. When the motor is working in the car, it pulsates in all speeds. The motor "speeds up" for about a second and then it returns to it's selected speed for about two to three seconds. I checked the codes and there are two: 161 & 233. I did change the resistor with no results. Any ideas on a solution? Thank you.

 

Any luck with this?