Just out of nowhere I have a check engine light on my 1994 850 Volvo.
I have the ability to read the codes on the fault diagnosis modules.
I got three faults
1 Drivers side damper motor position sensor open circuit or shorted to 12 volts
2Drivers side interior temp.sensor inlet fan seized
3 No control signal to blower fan power stage

I can find no reference in the manual as to the blower fan power stage. I know where the inlet fan is , but there must be a trick to removing the grab handle! Could use any ideas anyone has.
It almost sounds like a short or something. What can I check?? Help please!!

If you have some canned air sometimes just blowing some into the sensor hole will clean it up and get the fan spinning again. Don't stick the tube too far into the hole or you will damage the thermister.

None of the ECC codes you listed will turn on the check engine light. For a CEL you need to look for codes in A1, A2, and A6.

But, you do have a problem with the ECC.

To remove the grab handle, pry down the plastic covers on both ends of the bottom of the grab bar to reveal bolts. The small plastic temp sensor cover then lifts out and up. The insides are very fragile, so be careful. A lot of us have just used a vacuum cleaner to suck out the dust. I used a wooden toothpick to help things along and cleaned off the fan blades and sensor tip.

The resistor is in the firewall, left of the blower. About $100 for a new one.

The damper motor is behind the driver side of the dash. An ugly place to get to, upside down and backwards. If you replace the motor, it is quite involved. The new motor, about $250, must be in the same position as the old motor as far as vent direction goes. I believe that the vent comes in the heat position or floor and the vent must also point to floor. NEVER run the vent motor without it being attached to the vent, it will destroy the position indicators internal to it.
After replacing the vent motor, you will need to go through an aligning procedure outlined in Haynes manual. Quite lengthy.

Klaus
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Proud owner of a 220S. If I had more room, I would have more Volvos.

Thank you for the info and your promptness!!! Have tried to pry the ends off the grab bar and it's either very hard to do or stuck! Afraid to damage the headliner or worse! Thanks again! 850 Lady

The bottom ends of the grab bar have a plastic cover that is hinged at the bottom. Try sliding a very thin screwdriver or pocket knife into the vertical crack. You should not be near the headliner.
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Proud owner of a 220S. If I had more room, I would have more Volvos.