I own a 2003 Honda Civic LX the mileage is 80,000km. Show SPONSORED LINKS Do you have the same problem? Yes No Tuesday, October 30th, 2007 AT 9:08 PM January 02, 2014Updated: December 12, 2021By: Abraham Torres-ArredondoArticle ID: 532
In this tutorial, I'll show you how to test the blower motor and blower motor relay on 2001-2005 1.7L Honda Civics in a step by step manner. 8 times out of 10, when the blower motor stops working, it's the motor itself that has fried but not always. Other components that can fail, and cause the blower motor to stop working are:
With this tutorial's, you'll be able to test them all and get to the bottom of the problem. NOTE: If you have already tested your Honda Civic's blower motor (and it's good) and need to just test the blower motor resistor (known as the blower motor power transistor), then the following tutorial will help you test it:
You can find this tutorial in Spanish here: Como Probar El Motor Soplador Del Aire Acondicionado (1.7L Honda Civic) (at: autotecnico-online.com). To understand the how and why of the tests in this tutorial, it'll help if we know how your Honda Civic's blower motor works. In a nutshell, when you turn your Civic's ignition switch to the ON position:
Testing the blower motor and the blower motor relay isn't hard. Let's start with the first test. TEST 1: Checking The BasicsTo get your Honda Civic blower motor diagnostic on the road, in this first test we'll check 3 specifics things. One, that the blower motor relay fuse in the under-dash fuse box is not blown. And two, that the blower motor fuse in the under-hood is not blown. We'll also verify that the blower motor is really getting the juice (the blower motor relay is sending) when the key is in the ON position. These are the test steps:
Let's take a look at your test results: CASE 1: Both fuses were not blown and power is present on the BLU/WHT wire. This is the correct and expected test result. More importantly, it tells you that your Honda Civic's blower motor relay is OK and not the cause of the issue you're having with the inoperative blower motor. Your next step is to bypass the blower motor resistor (known as the blower motor power transistor) and check the blower motor directly. For this test go to: TEST 2. CASE 2: One (or both) fuses were blown. Replace the fuses and retest. Now since fuses don't get blown for no particular reason, you'll need to find out why they blew in the first place since there's a good chance you've got a short in the circuits those fuses are protecting. CASE 3: Both fuses are OK but power was NOT present. This usually indicates that the blower motor relay is bad. The blower motor relay can be tested. For this test, go to: TEST 3: Testing The Blower Motor Relay (Part 1). TEST 2: Bypassing The Blower Motor ResistorIf you've reached this point, you have confirmed that your Honda Civic's blower motor is getting power on the BLU/WHT (or GRN/WHT) wire of its harness connector. In this test step, we're gonna' bypass your Civic's blower motor resistor and see if the blower motor will turn on when you open the ignition switch. The basic idea here is to add power and Ground to the blower motor without removing it from its location under the dash. Adding power power is the easy part since it involves just opening the ignition switch. To add Ground to the blower motor, we need to bypass the blower motor resistor (known as the blower motor power transistor). IMPORTANT: For this test to work, you must be certain that the blower motor is getting power when you turn the key to the ON position (position II) on the BLU/WHT wire (or GRN/WHT wire depending on your specific Honda Civic) of the blower motor's 2 terminal connector.
Let's take a look at what your test results mean: CASE 1: The blower motor came on when you turned the key to the ON position. This test result tells you that the blower motor is OK and that the reason it's not coming on is due to a possible problem with the blower motor resistor (known as the power transistor). Thankfully, you can test your Honda Civic's blower motor resistor and thus be absolutely sure that it's fried and behind the cause of the ‘no blower’ condition. The following step-by-step tutorial will show you how to test the blower motor resistor (power transistor):
CASE 2: The blower motor DID NOT come on when you turned the key to the ON position. This test result tells you that the blower motor is fried and needs to be replaced. Here's why: So, far, you have:
So, taking all of the above into account, the blower motor should have turned on when you opened up the ignition switch. Since it did not, you can correctly conclude that the blower motor is bad and needs to be replaced. What can cause a blower motor to stop working?In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor.
Is there a fuse for the blower motor?Fuse Protection
To protect the blower motor power circuit, a 20-, 25- or 30-amp fuse is usually located in the fuse panel under the dash. The rating of the fuse will depend on the vehicle application and how much power the blower motor requires at full speed.
Is there a relay for the blower motor?In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.
|