here is something I save in my disk.. hope this help in solving your problem

Heater Fan:

The heater/ac fan just stops after 30 sec. to a minute of use. It started this summer and only happened. When the outside temp was above 90deg F. Now happens regularly whenever the AC is used. Getting To be the time of year in the Northeast when a heater fan will be a necessity. Any one else experienced this? Shut the engine down, and the fan will begin to work again but only for a short time. Got codes 211, 411, and 414 out of the diag unit. According to Haynes, these codes correspond to:

211 Drivers side damper motor position sensor
411 Blower motor fans seized or excessive current
414 Drivers side interior temp sensor inlet fan seized

Any thoughts on this would be greatly appreciated.


Heater Fan
I have the same problem with my wife's 93/850. The problem started during summer time when using the AC, and I heard a clicking on and off sound. I think the problem can be either one of 3 items. Go to volvospeed.com and look under bay 13 and notice how to remove the glove box. The relay, fan motor, and some kind of resistor for the fan motor are found behind the glove box. My intention is to jump the relay first and adjust the fan speed to maximum and see what happens. If the fan stops (relay ok), I would check the resistor pack by jumping straight current to the blower. If the blower works, the resistor pack would need changing. The fault in the driver sensor would not interfere with the fan because I have the same fault for the past two years and never bother the fan speed before. If you find the proper solution, please drop me a message. I hope this helps.



Heater Fan Replacement 850 1997

Just did mine. Quite easy. Parts were $140 shipped from
Volvoparts.com (you will have to call to order). Order
The assembly with the cage (not just the motor).

Disconnect battery

Remove glove box.

Remove lower panel.

(You may have to remove panel to remove box, or vice versa, I forget).

Remove knee bolster.

Blower is behind glove box. Unbolt and drop it down. Replace with new unit.

Re-connect battery

Test.

Re-assemble. Be careful of putting it all back well or you
Introduce rattles.

You need torx screwdriver and 13mm socket (as I recall).

Took me less then an hour