I have recently purchased a '03 Impala. A couple days ago I noticed when I turned on the fan for the heater it did not come on on any setting(1-5) Also the rear defog and the AC would not come on. If I turned the selector dial to the defrost setting the AC compressor would come on but still no blower fan. After driving 10 minutes or so, the blower fan started working. The same thing has happend 2 more times. IS there a probpem that anyone is aware of with this component on the Impala or other chevy models?
Whenever the blower motor fan doesn’t work it’s usually due to a failed blower motor resistor block.
This is located close to if not attached to the blower motor and after removal of two screws and wiring harness, it comes out.
Blower problems are common though I think they usually come up in models a few years older than yours. If some of the speeds for the blower don’t work, or the blower doesn’t work at all, then there usually is a problem with the resistors as Roadrunner stated. Since the blower does work at times then this means that there is a bad power connection to the blower somewhere or the motor itself is having a problem. When the motor does work and you can select any speed for it then the resistors are ok and you need to find the bad connection to the motor. The blower relay is a common failure point and this does sound like a relay problem. You may be able to swap the relay with another to prove that. If that doesn’t work then check for a bad connection in the switch. By running power directly to the blower motor you can see if it is ok.
But, roadrunner, he said that it blows sometimes and even if the resistor was bad it should blow on hi, right?
I had the same problem with a different car. The blower would work most of the time, but sometimes didn’t (on any speed). The problem turned out to be the blower motor itself.