Problems with your Honda Civic air vents or climate control always seem to rear their ugly head right in the middle of summer, or when you need it the most. When your Civic air vents don’t work, or they are stuck at one speed the last thing you want to do is drive your Honda. These issues can be caused by your climate control unit, or your Honda Civic blower motor. Today I’ll be showing you how to troubleshoot your blower motor in a 2006 Honda Civic EX with a 1.8 liter SOHC VTEC engine in it.
This How To guide will show you the steps to troubleshooting your Civic blower motor. You will need a digital multimeter to check this part. I’ll be showing you how to check the wiring harness from your Civic, as well as testing the resistor directly. This DIY tutorial applies for Honda Civics between the year ranges of 2001-2007.
When your Civic blower motor goes bad or fails on you, there’s a few problems you will have with your climate control.
Namely the dash controls won’t respond, meaning your air vents will only work at one speed. Because the FA or FG Honda Civic chassis incorporates controls and climate control visuals into your dashboard, you are going to need to remove the glovebox to access your blower motor resistor. The Civic blower motor uses this resistor to scale down the voltage or the speed of your air vents. Eventually the Civic Blower Motor resistor will burn out, leading to partial or complete failure of your climate control.
When this happens you’ll be using this tutorial to test both sides of the blower motor equation.
Testing your Civic Blower Motor Harness
Your resistor unit is connected by a four pin harness. This is plugged in behind your Honda Civic glovebox. You’ll be testing the pins using the Honda Civic blower motor wiring diagram below.
Once you gain access to your blower motor connector, disconnect the harness and turn your ignition key to the ON position. The first wire you will be checking is WIRE C which is a BLUE wire with a RED stripe. This wire runs to your heater control panel, and to activate this wire turn the climate controls on. You can do this with the engine started as well if you wish.
Don’t forget that you are testing the ENGINE harness or car side of the connector. This wire should be sending voltage from the control panel in your Honda Civic.
The next wire to check is WIRE B which is a solid BLACK wire. This wire in your blower motor should be for your chassis ground.
The rest of the Honda Civic wiring schematic works out to WIRE A which is a BLUE wire with a YELLOW stripe that provides the varying current to increase or decrease the fan speed. The last wire is WIRE D which is a BLUE wire with a BLACK stripe and that leads to the resistor for the base voltage.
Now you will be testing the resistor portion of your blower motor. Make sure that you are testing just the blower motor side for this next section of our DIY tutorial.
Testing your Civic Blower Motor Resistor
Because the resistor is basically an adjustable power transistor, you can test the unit directly by measuring the pins for resistance. This is done through your multimeter by turning the dial to measure OHMs. For this leg of our How To tutorial, you will need to turn your ignition to the “OFF” position.
You are now looking at the front of the blower motor resistor. The wiring schematic here shows you what pins you will be probing to measure the internal resistance.
There are two bolts that hold your power transistor in place. Undo these bolts and gently remove your Civic blower motor. Now you will be using your multimeter leads and probing pins C and D for resistance.
If your Honda Civic Blower Motor Resistor is still good, it will read between 1,400 to 1,500 Ohms.
The resistance here isn’t exact but it should be between the 1.4K and 1.5K range. If your resistor reads differently, it’s time for a replacement Blower Motor resistor.
Have any questions about this How To guide? Is your Honda Civic still having air vent issues or climate control problems? Leave us a comment below and let us know!
