Testing the blower motor, to find out if it's defective or not, involves 2 simple tests.
In this tutorial I'll explain, in a step-by-step way, both tests to help you find out if the blower motor is bad or not.
NOTE: This tutorial applies to the 2001, 2002, 2003, 2004, 2005, and 2006 Dodge Stratus and Chrysler Sebring equipped with a 2.7L V6 engine.
Contents of this tutorial at a glance:
You can find this tutorial in Spanish here: Cómo Probar El Motor Del Soplador (2001-2006 Dodge Stratus) (at: autotecnico-online.com).
NOTE: You can find the blower motor circuit diagram here: Blower Motor Circuit Diagram (2001-2004 2.7L Chrysler Sebring And Dodge Stratus).
Blower Motor Basics
When the blower motor fails in your Dodge Stratus (Chrysler Sebring), it'll usually fail in one of two ways:
- The blower motor will stop working completely.
- The blower motor will run, but run with a lot of bearing noise.
Since the blower motor is a simple 2 wire component that needs power and Ground to run; testing it is a very simple affair.
In this tutorial we'll test its amperage draw and then we'll make sure it runs by manually applying power and Ground to it.
TEST 1: Testing The Amperage Draw Of The Blower Motor
As the blower motor ages, it requires more amperage to run. After a certain point, if it's using too much amperage, it'll burn out the blower motor fuse, or the blower motor resistor, or the blower switch.
The maximum amperage draw of the blower motor is 30 Amps. This specification is based on its fuse rating.
We can very easily and accurately test the blower motor's amperage draw by measuring its resistance with a multimeter in Ohms mode.
Once we have the blower motor's resistance value, we'll use Ohm's Law to calculate it's amperage draw (Ohms Law: Amps=Volts ÷ Ohms).
NOTE: If you don't have a multimeter and need to buy one, check out my recommendations here: Buying A Digital Multimeter For Automotive Diagnostic Testing.
Let's get started:
Disconnect the blower motor from its electrical connector.
Place your multimeter in Ohms mode.
Measure the resistance of the blower motor with your multimeter. You'll be testing across the blower motor's connector and not the vehicle's wiring harness connector.
Divide 12.5 by the resistance value you got in step 3 (12.5 is the battery voltage value). The result of this calculation is the amount of amperage the fan motor is using.
To be a little more specific: Let's say that the resistance reading was .4 Ohms. This is what the math would look like: 12.5 ÷ .4 = 31.25 and this would translate to 31.25 Amps.
Let's take a look at your test results:
CASE 1: Your test result resulted in a calculation of under 30 Amps. This is the correct and expected test result and let's you know that the blower motor amperage draw is within specification.
The next step is to manually apply power and ground to the blower motor itself. For this test go to: TEST 2: Applying Power And Ground To The Blower Motor.
CASE 2: Your test result resulted in a calculation of 30 Amps or more. This test result tells you that the blower motor, on your 2001-2006 Dodge Stratus (Chrysler Sebring), is defective and needs to be replaced.