'98 Civic LX sedan. The AC/Heat doesn't blow on the 1st or 2nd setting. It does however blow on the 3rd or 4th setting. Any idea on what could be the cause of this? Thanks.

 

I think your power transistor is no good. The way it is wired is that there are 3 resistors in a line. When you put it in the 1st setting, all three resistors are connected to the blower motor, giving it less power and making it blow less air. In the second setting, only 2 resistors are connected to the blower motor. In the 3rd setting, only 1 resistor is connected in the circuit. The fourth speed connects the blower motor to the power directly. If the 2nd resistor was to go out, 2nd speed and 1st speed wouldn't work. If the first resistor was to go out, 1st speed wouldn't work. And if the 3rd resistor was to go out, only 4th speed would work. I beleive your 2nd resistor has gone out. The power transistor (the part i was explaining) is located somewhere in the blower motor assemby under the dash on passanger side. I can look it up for you tonight when i get home.

 

Thank you. I would appreciate it. Can the individual resistors be replaced, or is it more common to replace the whole assembly?

 

So i got a picture of where the resistor pack is located. It is not a transistor but actually a resistor pack. There are 3 resistors as a I previously mentioned. As far as whether you can change the resistors, that is going to be a little bit complicated. I doubt you can go the dealership and pick up the resistors. It is also going to be hard finding out the value of the resistor since it is burned out and will show an infinate resistance on a meter. Also, the resistors are most likely located on a circuit board, so you will have to desolder than resolder the resistors. However, I have never directly dealt with this resistor back before, I know how it works in theory but I've actually never worked on it before. You can see from the picture where the resistor pack is located. It should be on the right hand side of the passanger seat, under the actual blower motor. You may have to take out the blower motor and the resistor pack as one unit. You can check around and see if you can buy the resistor pack seperatly. There is a connector that goes into thee so it might be a servicable part. Tell me how it goes, I'm curious to see of you can change the individual resistors. If you need any more help, just ask and I'll see what I can do.

 

Here is calculator for resistor color codes. http://www.csgnetwork.com/resistcolcalc.html Hopefully they will be color coded. Otherwise, they may all be identical so you could measure all of the good ones and find out. Be sure to get one of the same wattage range(physical size is a good indicator of this, same size should be similar wattage). Also readings you get trying to measure resistors in circuit, could be wildly inaccurate(or harmful to other components) due to other possible routes for the current your meter is sending thru. Do your best to isolate it(them) before testing.

 

I totally forgot about the resistor codes, good catch. If you disconnect the blower motor assembly, you can do resistance tests with no worries.

 

Verify with a local dealer, but your part should be as listed....




005
RESISTOR, BLOWER
79330-SR3-A01
$27.88
001

Majestic Honda sells it for $20.50 plus shipping.

 

Hey y'all - down here in TX and its gettin mighty HOT. 01 EX Coupe - just bought at auction - no blower at all... AC light comes on and the compressor sounds like it is kicking in.

Any ideas???

 

This is to address the original problem posed by NS. I had the exact same problem in my 98 Civic EX -- blower works on fan control 1 and 2, but not 3 and 4. It is definitely the blower motor resistor. Very easy to replace.

Both Napa and Autozone have the part.

Napa: ECHBR11
Cost: $27.49
Link: http://www.napaonline.com/masterpage...Motor+Resistor (I provided this mainly because it has a picture of what this resistor pack looks like)

Autozone:
Cost: $26.99
Link: http://www.autozone.com/R,APP1219055.../addToCart.htm

There are probably cheaper online sites, but if you prefer to buy local just in case you need to return it.

How to replace:

The blower motor sits under the passenger side dash. The blower motor resistor sits right behind the glove compartment. Empty out your glovebox and open it wide open so it exposes the blower motor. To do this, just push in the right and left side of the glovebox so that the little catches on both sides disengage. It'll still be hinged at the bottom, but the entire compartment should drop straight to the floor. On the top right hand side of the blower motor, you'll see a wirepack going to the resistor. The resistor (the back of it) will look like a rectangular plate held in place by two philips screws. Unplug the wirepack and remove the two screws -- you'll need a stubby phillips screwdriver. The resistor will pull right out.