In this tutorial I'm gonna' show you how to test the blower motor control switch without having to remove the A/C Heater Control Panel to test it.
You'll be able to find out if the blower switch is bad or not with 4 simple 12 Volt test light tests (which are done on the blower resistor assembly's electrical connector).
All 4 tests are not hard and I'll explain how to do them in a step-by-step way.
Contents of this tutorial at a glance:
APPLIES TO: This tutorial applies to the following vehicles:
- 2001-2004 2.4L DOHC Chrysler Sebring 4-door sedan.
- 2002-2004 2.4L DOHC Chrysler Sebring Convertible.
- 2001-2004 2.4L DOHC Dodge Stratus 4-door sedan.
The following tutorials may come in handy:
- How To Test The Blower Resistor (2001-2004 Sebring And Stratus).
- How To Test The Blower Motor (2001-2004 2.4L Sebring And Stratus).
NOTE: You can find the blower motor circuit diagram here: Blower Motor Circuit Diagram (2001-2004 2.4L Chrysler Sebring And Dodge Stratus).
Blower Motor Control Switch Basics
As you can see from the photo at the beginning of this tutorial, the blower motor control switch has 5 speed options. These are 0 (OFF), 1 (LO), 2 (M1), 3 (M2), 4 (HI).
In a nutshell the blower motor control switch is the component that channels current thru' the blower motor resistor assembly so that 4 different blower speeds are possible.
To be a bit more specific this is what happens when you select a blower speed:
- When you select speed 1 (LO), the current is channeled through three resistor coils in the resistor block.
- When you select speed 2 (M1 -medium 1), the current is channeled through 2 resistor coils in the resistor block.
- When you select speed 3 (M2 -medium 2), the current is channeled through one resistor coil in the resistor block.
- When you select speed 4 (HI), the current bypasses all of the resistors of the blower resistor assembly.
CIRCUIT DIAGRAM: To get a better idea of these different circuits, take a look at the blower motor circuit diagram here: Blower Motor Circuit Diagram (2001-2004 2.4L Chrysler Sebring And Dodge Stratus).
TEST 1: Testing The Blower Switch Speed 1 (LO) Circuit
NOTE: The blower resistor connector in photo 1 of 2 has heat damage (the insulation on wires 1 and 2 is melted). If the connector on your vehicle looks like this, then you can conclude that the blower resistor assembly is bad and both it and the connector should be replaced. You'll need to check the amperage draw of the blower motor too.
For our first test we're gonna' make sure that the speed 1 (LO) circuit inside the blower control switch is OK.
We'll accomplish this test by testing the TAN wire of the blower resistor assembly's connector with a 12 Volt automotive test light.
The TAN wire is identified with the number 5 in the photo above.
If the speed 1 (LO) circuit is OK (in the blower switch), the 12 Volt test light should light up.
If the speed 1 (LO) circuit has a problem (in the blower switch), the 12 Volt test light will NOT light up.
NOTE: It's important that you back-probe the blower resistor connector instead of probing the front of it. Probing the front of the blower resistor assembly's connector can damage the female terminal. Back-probing, which is touching the rear of the connector where the wire enters the electrical connector, is the safest way of testing the terminal.
These are the test steps:
Disconnect the blower resistor from its electrical connector.
NOTE: This and all the other tests are done with the ignition key in its OFF position.
Select blower motor speed 1 on the AC/Heater Control Panel.
Connect the 12 volt test light's alligator clip to the positive (+) battery jump start terminal in the engine compartment.
The positive (+) jump start terminal is on the under-hood fuse box (see photo 2 of 2 above).
Back probe the terminal that connects to the TAN wire of the resistor block's connector with the metallic point of your 12 Volt test light (see photo above).
NOTE: Avoid probing the front of the female terminal of the connector or you run the risk of damaging it with the tip of the 12 Volt test light.
The 12 Volt test light should come on if the speed 1 (LO) circuit is OK.
Let's examine your test result:
CASE 1: The 12 Volt test light turned on. This is the correct and expected test result. You can conclude that the speed 1 (LO) circuit is OK within the blower motor control switch.
The next test is to check that the speed 2 (M1) circuit inside the blower motor control switch is functioning correctly. For this test go to: TEST 2: Testing The Blower Speed 2 (M1) Circuit.
CASE 2: The 12 Volt test light DID NOT turn on. This lets you know that the speed 1 (LO) circuit is bad within the blower motor control switch. Replace the blower motor control switch.