One of the components that you're gonna' have to replace sooner or later on your 3.8L equipped GM car is the blower motor.
Thankfully, testing the blower motor is one of the easiest tests you can do on your car.
NOTE: Even though this tutorial is filed in the GM 3.8L index of this website... this tutorial applies to some 1992 and 1993 Cadillac vehicles. This is because this particular blower motor was used in several models from 1992 to 1999. To find out if your particular GM vehicle is covered by this troubleshooting tutorial, check the box titled “Applies To:” on the right column.
Here are the contents of this tutorial at a quick glance:
- TEST 1: Applying Battery Power And Ground To The Blower Motor.
- Where To Buy The Blower Control Module and Save.
- More 3.8L GM Tutorials.
You can find this tutorial in Spanish here: Cómo Probar el Motor del Soplador del Aire Acondicionado (3.8L GM) (at: autotecnico-online.com).
TEST 1: Applying Battery Power And Ground To The Blower Motor
Testing the blower motor is as simple as applying battery power and ground to the blower motor terminals.
Depending on the exact location of the blower motor (on your specific 3.8 liter equipped GM vehicle) you can test it on the car or you may have to remove it for ease of access.
As a safety precaution you should use a fused jumper wire or a power probe to apply battery power to the blower motor.
In case you're wondering, you can create your own fused jumper wire by using an inline fuse holder that you can buy at your local auto parts store.
Alright, these are the test steps:
Disconnect the blower control motor from its 2-wire electrical connector.
You'll notice that 1 of the 2 wires that comes out of the blower motor connector is purple (PPL) and the other is black (BLK).
The PPL wire is the one that provides the blower motor with battery power. The BLK wire is the one that feeds the blower motor ground.
Connect a jumper wire to the blower motor male spade terminal that connects to the BLK wire of the connector.
The other end of the jumper wire should connect to chassis ground or directly to your vehicle's car battery negative terminal.
Connect a fused jumper wire to the blower motor male spade terminal that connects to the PPL wire of the connector.
The blower motor should run as you soon as you connect the other end of this fused jumper to your vehicle's car battery positive terminal.
Let's take a look at what your test results mean:
CASE 1: The blower motor ran when you applied ground and battery power. This is the correct and expected test result and tells you that the blower motor is good.
If you're having issues with the blower motor not working it's possible that the blower control module is bad and needs to be tested. If you're vehicle is equipped with a blower control module and NOT a blower resistor... the following tutorial will be helpful:
CASE 2: The blower motor DID NOT run when you applied ground and battery power. This test result tells you that the blower motor is bad and needs to be replaced.
The next subheading will show you where you can buy the blower motor and save a few bucks.
Where To Buy The Blower Motor And Save
There's a good chance that you can buy the original AC Delco blower motor online for a whole lot cheaper than somewhere local.
The following links will help you comparison shop for the blower motor:
More 3.8L GM Tutorials
If you enjoyed and/or found this ‘How to’ article helpful... I have written several more 3.8L specific test articles. You can find a complete list of 3.8L tutorials here: GM 3.8L Index of Articles.
- How To Test The Fuel Injectors (GM 3.8L).
- How To Do A Fuel Injector Noid Light Test (GM 3.8L)
- How To Test The 3.8L GM Crank Sensor With A Multimeter.
- How To Test The Cam Sensor -P0341 (GM 3.8L).
- How To Troubleshoot A No Start (GM 3.8L).
- GM 3.8L Ignition Control Module and Crank (3X, 18X) Sensor Test (at: easyautodiagnostics.com).