Fan blower only works on some speeds

Hi, I have a 1997 Chevy Cavalier with 141,000 miles. I was just wondering about the fan blower. It has 4 speeds, but only works normally on the highest 2 speeds. The lowest speed works very weakly, and as I accelerate more while driving it gets stronger. If I’m idling, nothing comes out, but if I’m going 70 it’s almost normal. The 2nd speed doesn’t work at all.

I was just wondering if it could be something I can fix myself. I’m a fairly beginner car fixer.

You need to replace the blower resistor. Then you’ll have all four speeds again. This is an inexpensive part avialable at any auto parts store.

Sounds great! Thanks for the quick reply!

If you want to start fixing things yourself this is a good one for learning certain kinds of diagnoses and repair procedures.

At an auto parts store get a Haynes or Chilton’s repair manual for the car. Also buy a digital multimeter (I’d spend at least $20 or more on a known brand but you can spend as little as $10). Find the manual section on heating & A/C and follow directions for testing the power for the fan / resistor / switch.

Mcparadise is likely correct, btw, but it is also possible that your problem is in the switch rather than the resistor. There are ways to find out for sure and if you go through the process you’ll learn stuff.

When the replacement resistor fails (may take some time), replace both it and the blower motor.

The reason the air flow is normal at high speed when the sw. is on the low setting is that ram air is moving through the intake air ducts.

My '91 Camry did the exact same thing and the dealer and NAPA both wanted $80 for the replacement part; housing with 3 resistors. Two of the resistors were burned up, the third was OK. Hightest fan speed is a direct 12V and bypasses the resistors.

I went to Radio Shack and got 2 packs of ceramic 10 ohm resistors for $9. I could get only one of them to fit so I have Low, Med, High now. The first resistor lasted 3 years. It takes me about 15 minutes to pull the plastic holder, cut out the old resistor and solder in a new one.

Ok, so I’m cheap. I still have 2 resistors left which should last me for a while, all for $9.


You sir are a true blue all american boy, you done good.

Since it is a GM product, you can cure the product by replacing the blower resistor. If you had a Lincoln, its blower is designed to run on all of the speeds some of time, some of the speeds all the time, but not all the speeds all the time. At least that is what I have been told. (I couldn’t resist this post–particularly since in involves blower resistors).

Thanks for the info. I would like to start doing more for my car myself, so this does sound like a good place to start. Kind of excited about it.