When checking voltage to a motor or solenoid, I never use a voltmeter, I use a test light....voltmeter just shows potential voltage, not working voltage....for example, suppose there is a voltage drop in this particular circuit....a voltmeter, reading open ended voltage would read the source voltage, say it's 12 volts...but you attach a test light and it's very dim, or not lit......if you were to take a test light and attach it across a battery, it would be very bright, because all the voltage is dropped across the test light.....but in this case, because there is a voltage drop somewhere in the circuit,, only a portion of the 12 volts is across the test light, making it dim or unlit....
In other words, because of a large voltage drop elsewhere in the circuit, current is low, and not enough to light the test light or turn the blower....