Climate Control knob question

[ziazhp]

I can only sense/hear air coming when the climate control blower knob is turned all the way to high (position 4). No air comes out on either of the other positions. Temperature works well. What would be the cause of this?

[Yeltsew7]

My car is doing the same thing. I'm assuming it's the resistor pack that the switch goes to. Speed 4 has no resistance, so that's why it's the only one that works.

I ordered this and am hoping that it will work.

http://www.rockauto.com/en/moreinfo.php?pk=4818621&cc=1011698&jnid=376&jpid=0

Sent from my LGLS992 using Tapatalk

[mr.vang]

Your fan resistor is dead. 123 doesn't work but 4 does indicated a dead resistor.

[Seawolf]

Agree with Vang, though you might not see broken wires on the resistor pack.

Most of the failures I've seen are burnt/oxidized thermal switch contacts or between the common speed 1,2,3 power connector and the securing rivet (located at the outer end of the thermal switch).

The resistor pack is cheap enough but you can just try cleaning the contacts or drilling the rivet out and replacing with a small brass machine screw and nut.

Final note: Burn't connections in either of these locations may indicate high motor resistance, in which case you may be looking to replace the blower motor in the not too distant future.

[ziazhp]

Ok update. My E30 is not a daily, but once the car warmed up I noticed that all four work fine, but when cold, as stated above, only number 4 works. So definitely resistor or motor too?

Agree with Vang, though you might not see broken wires on the resistor pack.

Most of the failures I've seen are burnt/oxidized thermal switch contacts or between the common speed 1,2,3 power connector and the securing rivet (located at the outer end of the thermal switch).

The resistor pack is cheap enough but you can just try cleaning the contacts or drilling the rivet out and replacing with a small brass machine screw and nut.

Final note: Burn't connections in either of these locations may indicate high motor resistance, in which case you may be looking to replace the blower motor in the not too distant future.

[Das Delfin]

^ I mean.. why would the heat work before the car is warmed up? You do realize the heater gets its heat from hot coolant circulating the motor? And the coolant gets hot when the motor warms up.. so how could you have heat before the car is warm?

[ziazhp]

^ I mean.. why would the heat work before the car is warmed up? You do realize the heater gets its heat from hot coolant circulating the motor? And the coolant gets hot when the motor warms up.. so how could you have heat before the car is warm?

Meaning air came out, not heat. Sorry for the confusion. When the car is not up to operating temperature the air does not come out of the first three settings, only four. When the car is warmed up air comes out of all four. Does that make sense?

[Das Delfin]

that's really weird. Can you hear the blower motor turning in positions 1-3? You ususally can't feel air coming through in pos 1 even with your hand to the vent. But the blower motor is independent of the motor's temperature.

Can you feel air flow when parked, after the car has warmed up? Or only when driving? Because when driving, air will flow through the vents even with the blower motor off

[Seawolf]

....So definitely resistor or motor too?

Pull the resistor and check for continuity across all connections first. If you find resistor problems then fix or replace this first - it's cheap and relatively easy to replace.

The blower motor is not so cheap or easy to replace, but you may land here if the resistor proves to be okay.

[ziazhp]

that's really weird. Can you hear the blower motor turning in positions 1-3? You ususally can't feel air coming through in pos 1 even with your hand to the vent. But the blower motor is independent of the motor's temperature.

Can you feel air flow when parked, after the car has warmed up? Or only when driving? Because when driving, air will flow through the vents even with the blower motor off

When the car is warmed up, I can feel air coming through 2-4, very lightly through 1 and can heat the blower for sure. I can also feel it and everything works regardless if the car is parked or not. It's weird, it's like the air comes out only when the car has reached peak operating temperature (for 1-3) that is, 4 you can always feel something but of course it won't be warm until the car is warmed up. Final Stage resistor, motor? Both?

[reelizmpro]

I have never had to buy a new resistor pack in over 20 years of ownership. I have fixed them all by simply resurfacing the contacts. It's nothing but solid state coils of various resistances. Worn brushes on the motors are another matter but I have had goodluck just cleaning and lubricating them.

[Das Delfin]

When the car is warmed up, I can feel air coming through 2-4, very lightly through 1 and can heat the blower for sure. I can also feel it and everything works regardless if the car is parked or not. It's weird, it's like the air comes out only when the car has reached peak operating temperature (for 1-3) that is, 4 you can always feel something but of course it won't be warm until the car is warmed up. Final Stage resistor, motor? Both?

that's very interesting. Does your fuse 20 ever blow? Check and see if it or its place in the fuse box is partially melted. A sign of an aging blower motor is an increased current draw, which creates heat and most of the time that heat shows up right at fuse 20.

If you wanted to replace the resistor for kicks they're like $20 so it's no big deal.

tbh I have no idea what's causing your problem.. broken blower fan blades possibly? Maybe a mouse made its home and is restricting air flow from the heater core to the blower? But sometimes with these cars you'll replace one thing and it'll fix something completely different (especially with electrical) so I wouldn't hesitate to throw a new resistor in for cheap insurance. Either way get in there and see what's going on.

[george graves]

Agree with Vang, though you might not see broken wires on the resistor pack.

Most of the failures I've seen are burnt/oxidized thermal switch contacts or between the common speed 1,2,3 power connector and the securing rivet (located at the outer end of the thermal switch).

Yea, you might be on to something - like 10 years ago I fixed one by soldering a thick jumper wire onto it. Worked like a charm on all speeds. I think it might still be in my car.

Next time I have a borken one out of a car I'll see if there is an easy DIY fix I can share. (or someone else can look into it)