Hey guys brand new here, so bear with me if something similar has already been answered. I have a 94 s10 blazer 4x4 4.3 with A/C.

For awhile I had an intermittent problem were the vents and defrost would only "leak" air instead of blowing air. It does not matter whether it is heat or cold air. This would only happen occasionally, but now I cannot get it to blow air whatsoever, just a weak leak of air. My first thought was the resistor in the blower motor, but now I am not sure. I was curious what you all thought. Is it the resistor? The brushes sticking? Or is the motor just blown? Any input would be appreciated thanks in advance.

p.s. this guy is kind of a work in progress, so I'm sure I will have plenty more problems down the road

 

There are a couple things it might be. From your description, its hard to tell if the blower motor is running or not, you only mentiona leakat the vents. With the engine not running, key on-only,you should be able to hear the blower motor, especially on high speed. If there is no change in the motorspeed when operating the blower speed control switch, then concentrate on the motor. Check fuses, checkthe ground wire (that was my issue), check voltage at the motor (at each speed), check the connectorat the motor also.If your getting different voltages when switching speeds but no blower function, then its probably time for a new blower motor.

If there is some voltage at the motor, but voltage does not change when selecting different speeds, then your problem may be with theblower speed switch, so start checking it out. My '90 blazerhas a couple screws on the bottom side of thecontrol panel that will let you access that area.

When you said"Vents", does that include the floor outlets, no air out of those either? If the blower is working and full air is coming out of the floor vents no matter which setting the control is on (defrost, heat, vent etc), then its probablya vacuum issue or a cable issue not controlling the blend/control doors properly.

Several years ago, I had a blower motor act up on me in a 79trans am. I'm not sure if it was the brushes or not,it required a boost to get it going.Not that I'm suggesting you do this, but I ran a power wire with a switch to the blower power connection. Once I had the car started and wanted fan, I'd set the speedswitch to high, then flip my extra switch on, blower would come on, I'dturn my extra switch off, and then theI could control it with the regular switch. Redneck Engineering.I eventually just replaced the blower. Figured it was less time consuming compared to having to pull it out and then tear it apart to change brushes.

 

Thanks for the input, It does not blow any air at all through any of the vents, defrost, or the floor heater vents. When I turn the ignition it does not blow any air, I cannot hear it anyway. The air that is leaking out is the very small amount that comes through the vents, even when you have the blower off.

Thanks for the info and advice, I'll get back to you when I get a chance to test all that.