This tutorial will explain how to test the blower motor resistor on the 1997-1999 Dodge Dakota and 1998-1999 Durango without having to remove the dash to get to it.
Yup, the blower motor resistor block can be tested without having to remove the dash!
The test is explained in a step-by-step way and will help you find out if it's defective or not.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar La Resistencia Del Soplador (1997-1999 Dodge Dakota Y Durango) (at: autotecnico-online.com).
NOTE: The 1997-1999 Dodge Dakota and Durango resistor block has 4 metal terminals. If you need to test the 5 terminal resistor block, see this tutorial: How To Test The Blower Motor (2000 Dodge Dakota).
For the 2001-2004 blower resistor block test, see this tutorial: How To Test The Blower Motor Resistor (2001-2004 Dakota, Durango).
You can find the blower motor test here: How To Test The Blower Motor (1997-1999 Dakota, Durango).
Blower Motor Resistor Basics
The blower motor resistor block is hard to get to, since this bad boy is located behind the dash (see photo above). The cool thing is that you don't have to remove it to test it.
When the blower motor resistor block fails, you'll usually see one of the following symptoms:
- Blower motor works in high-speed only.
- Blower motor works in some speeds, but NOT all speeds.
It's very common for the resistor connector terminals to corrode or for the connector to burn and melt. This will make disconnecting the connector from the blower motor resistor block very difficult.
Another common problem is finding the resistor block coils corroded or burned out when removing the resistor block for testing.
TEST 1: Resistance Testing The Blower Motor Resistor
To test the resistor block, without removing the dash panel, we're gonna' connect our multimeter test leads to specific female terminals of the blower motor switch connector.
The photo above is of the blower motor switch connector we need access to. This connector connects to the AC Heater Control Panel of your Dodge Dakota (Durango).
This means you'll need to remove the AC Control Panel from it's place, but you don't need to remove it completely, since we only need to unplug the 7 wire connector from it.
Testing thru' these two connectors will give us the same result as if we were testing directly on the blower resistor block itself.
NOTE: If you have removed the dash and are testing the blower resistor block itself, see the following section: Blower Resistor Continuity Specification Tables.
OK, let's get started:
Remove the AC Control Panel and disconnect it from its 7 terminal connector.
This is the connector that connects to the blower motor switch of the AC Control Panel.
Place your multimeter in Ohms mode.
Testing blower speed LO
Probe the female terminals of the wires labeled #3 and #6 of the blower switch connector.
Your multimeter should read continuity (I got: 1.0 to 1.1 Ohms).
Testing blower speed M1
Probe the female terminals of the wires labeled #4 and #6 of the blower switch connector.
Your multimeter should read continuity (I got: 2.7 Ohms).
Testing blower speed M2
Probe the female terminals of the wires labeled #5 and #6 of the blower switch connector.
Your multimeter should read continuity (I got: 0.5 Ohms).
Let's take a look at what your test results mean:
CASE 1: Continuity exists as indicated in the test steps. This is the correct and expected test result.
You can conclude, with these test results, that the blower motor resistor is OK.
If the blower resistor block were defective, you would have gotten an OL reading on your digital multimeter indicating NO continuity.
CASE 2: Continuity DOES NOT exist between some of the connector terminals tested. This test result tells you that the blower motor resistor is defective and needs to be replaced.