Hi,

I have a Volvo 940 st from 1995 with about 413000 ;-)

Recently, the heater fan stopped working. Although heat keeps on slowly coming out inside, this is a problem in the morning when I need to clear all windows and windscreen from frost (no fan no party....).

I've checked the fuses behind the ashtray and they all seem to be OK. Therefore, I believe that either the control panel or the fan itself are broken.

Can anyone suggest me how I can investigate the problem? Before buying any spare part, how can I find out where the problem is? Is there a tutorial or something telling me how I can access the fan and test it?

Thanks a lot in advance for your valuable help.

Marco

 

940 ST ? thats not a model I'm familiar with.

on the 7/9's, the fan is behind the dashboard on the passenger(right) side of the car. there's a resistor block on the outside of the fan housing which varies the speeds, the wires from the speed switch connect to this block, the resistors can fry, and this disables the fan, although the highest speed usually still works.

I'd probably find that R block and see if voltages are getting to the right pins ... if they are, and voltage is getting to the fan motor, then its the motor itself that died, you need to replace it. you remove the passenger kick panel and glove box to access the fan.


found this how-to, might be of some help.
How to fix a 740 940 heater motor resistor

when you get this far...
http://www.volvotips.com/wp-content/...r_interior.jpg

check the voltage at that blue connector when the fan is on different speeds. if you see voltage there (12V for high speed), then your fan motor is probably bad. if you don't see voltages, then check the resistor, and if there's no voltages going into the resistor, I'd be checking the power at the heater control panel (does this "ST" have manual or electronic climate control?)