hi all, fortunately volvo's are fairly reliable, so i haven't had to bother you guys for some years now, and you have come through for me in the past, so here's hoping, i had the air con on a few weeks back, and it just stopped, i checked the fault code and it was 4-1-9, faulty diagnostic signal from blower fan power stage, anybody had this problem before, as i don't even know where to find a/c relay or in fact anything asociated with a/c, but code will not reset, so i assume fault is still present, thanks in advance joe

The "power stage" is on the firewall, passenger side, just to the left of the blower. Quite expensive. If you move the fan speed switch, does the fan work?
If it only works on high speed, check the fuse first.

Klaus
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I still miss my 164 and my 854T. Just driving a V70R :)

thx for the reply and tip on where to find, but unfortunately not a movement in the fan at all, and all fuses ok, joe

Is this what you are looking for:
http://www.fcpgroton.com/product-exec/product_id/1691/nm/1993_1994_Volvo_850_Blower_Motor_Resistor_for_models_with_climate_control_/category_id/78


Klaus
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I still miss my 164 and my 854T. Just driving a V70R :)

There's probably some info in the 850 FAQ's about repairing/replaceing the power stage.

thx for the tips fixit do you think the p.s is knackered joe

Try tapping on the fan. The brushes loose contact with the armature when they get short. You may be able to loosen them up a bit.

ok will try, would that give the fault code as suggested, be good if it's only brushes, although i bet it's not easy to get to, joe