defroster stepping motor check

uncledave11 · Post by **uncledave11** » 01 Jan 2012, 16:32

Well it fiquires with winter fast upon us all those " little problems"

now get quick attention. Heater works great and i can get airflow at all positions of the climate control knob except....defroster. Little to no air flow yet I can hear the stepper moters shifting around as I can put the air anywhere except out the defroster vents!!

Anyone experience this problem too? Any diagrams and test proceedures would be very helpful and appreciated!

Thx,

Dave
95 850 Turbo

Post by **rspi** » 01 Jan 2012, 16:42

Hey Dave, when I select DEFROST I don't get much air flow either. Does your AC work? It is a big part of the Volvo defrost system.

uncledave11 · Post by **uncledave11** » 01 Jan 2012, 16:46

Very well! Only had to top it off this summer with 2oz 134a. you could hang meat in there in july!!

Post by **rspi** » 01 Jan 2012, 16:51

When you select DEFROST, does the AC kick on? My AC was leaking about 12 oz every month before I replaced the evaporator. I think this wagon leaks about 3 oz per month.

Post by **BEJinFbk** » 01 Jan 2012, 19:45

Hey, Dave - If you hear clicking, the motor is probably working, just not moving the flap.
The point where it's output shaft connects to the flap sometimes breaks, usually the "female" side.
There are several documented fixes - My favorite write up used small gauge wire to wrap around
the broken flap socket to reinforce the broken part. The plastic just breaks after a decade or so.
I'm not sure where that fix is hidden, ( It may be on VolvoSpeed...) but searching MVS will probably
turn up some good stuff anyway. There are a ton of great things here.

Here are some pages for your system:

95 850 ECC - both.pdf: (968.21 KiB) Downloaded 152 times

95 850 ECC maint instructions.pdf: (868.67 KiB) Downloaded 134 times

I'm pretty sure that you want to check out servo 6/47.
Hope this helps! Stay Warm!