This is from a Durango, not a Dakota, but since both vehicles have the same front ends, I'm hoping you guys can help me.

2003 Dodge Durango SLT
4.7 V8
Automatic

I just bought this vehicle. It's in good shape for its age and mileage, but it has a few issues that need sorting out. The blower motor was rigged to be constantly on. This was done by splicing a wire from the motor itself directly to ground.

This was done because the front blower motor control switch does not work.

The rear switch works. It has a rear blower for the back seats. That works fine. Taking apart the controls I found nothing damaged or burnt. The resistor pack was replaced not too long ago, and the blower motor obviously works. It's just not getting power from the switch for some reason.

 

the circuit is grd controlled...the switch supplies grd...the motor is supplied power at key in run.

unplug the c3 connector to the switch. key in run check for voltage at each pin on the wiring harness. there are 5 wires in the connector
-one is ground, black
-one is full battery voltage, dark green
-3 are reduced voltage from the resistor, light blue, light green, tan
if they all have the proper power...check with a voltmeter or testlight... either the grd is bad or the switch is nfg.

 

Okay. I assume the c3 connector is the one that plugs right into the switch. Wire colors are a bit different from what you listed.

I see black. and black with a green stripe (two thick wires) then green, orange, and blue.

Testing for voltages I got no volts going from black to black and green. Going from black to the other wires got me 4.5 to 6 volts. So I ran a jumper wire from black to one of the wires supplying voltage and nothing.

So... no 12 volt reading fom that connector, but I would think 6 volts would at least make the blower turn.

Or am I probing the wrong connector?

 

the mitchell diagram listed different colours. Here is the same info from dodge. the connector should be black and have 10 pins of which 5 are empty.

CAV CIRCUIT FUNCTION
1 C7 12BK/TN HIGH SPEED BLOWER MOTOR DRIVER
2 - -
3 C6 14LB M2 SPEED BLOWER MOTOR DRIVER
4 Z1 10BK GROUND
5 - -
6 - -
7 - -
8 - -
9 C5 14LG M1 SPEED BLOWER MOTOR DRIVER
10 C4 16TN LOW SPEED BLOWER MOTOR DRIVER

 

Yeah that's got to be the right connector then. 10 pins, 5 are in use.

So I'm getting no +12v from this connector, yet the blower motor is getting 12 volts because grounding it to the chassis makes it run at full speed when the key is on.

 

Any other ideas?

 

well there is the problem, the switch just provides ground, it has to get power coming into it.

go back to the next item inline...which is the blower resistor....check for power in and out of the resistor....the power in can be tested with the connector disconnected but to test power out leave the connector installed and backprobe the wires with t-pins.

if you have power in and out at the resistor, you must have broken wiring from the resistor to the switch....disconnect the wires from the resistor and blower switch and do continuity checks with a ohm meter.

 

Okay, let me make sure I understand what to do here.

So if I put the key in and set it to run, and hook up my multi meter with one lead to chassis ground, the blower motor resistor should be getting power from at least one terminal regardless of whether or not the switch is hooked up. if it's not then I have a bad wire. if it is then I have a bad switch.

Does that sound about right?


Okay did that. I get voltage readings all the resistor terminals, so it's clearly getting power, but not ground, which makes sense. The ground wire for the switch is connected, I get continuity to chassis ground from it.

So unless there's something else I can try, next up is the switch.

 

No. The blower motor resistor is ground switched. You need a multi-meter and measure the resistance within the resisotr block, or with it plugged in, back probe form connector to ground.

 

Here's the diagram.

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