And I don't know why! When I turn on the A/C, only the passenger side fan turns on. Could the fan motor be dead??

 

It could be a bad motor, no power/ground.

Unplug the electrical connector for that fan and turn on the a/c. Use a volt meter to see if there is 12V across the two pins. If you have 12V, then you fan motor is bad.

No voltage, then something is wrong upstream (fuse, relay, etc..) and you will have some more tests to do.

 

OK. I did exactly that, and I have 14.1 volts across the pins whenever the A/C compressor is running. No problem.

However, I made the mistake of unplugging the connector while the one fan was running. After plugging the connector back in, now neither fan works. Could I have zapped something when I unplugged the connector? I still have 14.1 volts across the pins, so the fans are definitely getting the signal to run. . .

 

UPDATE: It's definitely the fan motor. I tapped it with a hammer, and it feebly began to spin before it quite again. I also tapped the passenger side motor, and it started right back up again at full speed. . .phew!

 

Sounds like your passenger side motor might be next to fail?

 

Yeah. I'm thinking that too. On the bright side, it looks like they sell just the motor at the auto parts store, so at least I don't need to buy the entire assembly.

 

New fan motor installed. We're rolling again!