Does the blower motor run with the switch in the OFF position? If you leave the blower motor switched continually on you may not notice this.
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''If so '' I suspect that there is an earth fault on one of the wires connected to either pin 4 or 5 of the resistor.
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''If so '' I suspect that there is an earth fault on one of the wires connected to either pin 4 or 5 of the resistor.
+
''If not'' then it may be a faulty blower switch
Here is a the blower circuit for a 2002 Dodge Dakota. Hopefully it is the same for your particular year model.
[image|914786]
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With a DMM (Digital Multimeter - Ohmmeter function) remove the blower resistor and measure the resistance readings on the blower resistor module between pin 2 and pin 1 (should read 0 Ohms) then between pin 2 and pin 3 then 2 & 4 then 2 & 5 and see what they are reading to find out which one is failing.
+
With a DMM (Digital Multimeter - Ohmmeter function) remove the blower resistor and measure the resistance readings on the blower resistor module between pin 2 and pin 1 (should read 0 Ohms) then between pin 1 and pin 3 then 3 & 4 then 4 & 5 and see what they are reading to find out which one has failed.
I suspect that there will be no reading between pins 1 & 3. This is because this is the resistor which carries all the current when the switch is in positions low thru med 2.
However I am suggesting that if for example you had an wiring earth fault on pin 4 and the switch was on Med 2 then not only would you have the normal current flowing through the resistor connected between pins 1 & 3 BUT you would also have more current because of the circuit path available thru pin 4 (which shouldn't be there). This scenario is the same for pin 5 with the Med 1 position.
It could also be an internal blower switch fault and that there is a short circuit connection between either the low and Med 1 setting or between the Med 1 and Med 2 setting. Hi should not affect it as it is a short circuit through the resistor anyway. With the plug disconnected from the resistor measure back toward the switch between the wires for pin 3 & 4 (light blue and light green/yellow) and 4 & 5 (light green/yellow and tan). and rotate the switch. There should never be a reading between the wires with the switch in any position.
Does the blower motor run with the switch in the OFF position? If you leave the blower motor switched continually on you may not notice this.
-
''If so '' I suspect that there is an earth fault on one of the wires connected to either pin 4 or 5 of the resistor. ''If not'' then it may be a faulty blower switch
+
''If so '' I suspect that there is an earth fault on one of the wires connected to either pin 4 or 5 of the resistor.
+
''If not'' then it may be a faulty blower switch
Here is a the blower circuit for a 2002 Dodge Dakota. Hopefully it is the same for your particular year model.
[image|914786]
With a DMM (Digital Multimeter - Ohmmeter function) remove the blower resistor and measure the resistance readings on the blower resistor module between pin 2 and pin 1 (should read 0 Ohms) then between pin 2 and pin 3 then 2 & 4 then 2 & 5 and see what they are reading to find out which one is failing.
I suspect that there will be no reading between pins 1 & 3. This is because this is the resistor which carries all the current when the switch is in positions low thru med 2.
However I am suggesting that if for example you had an wiring earth fault on pin 4 and the switch was on Med 2 then not only would you have the normal current flowing through the resistor connected between pins 1 & 3 BUT you would also have more current because of the circuit path available thru pin 4 (which shouldn't be there). This scenario is the same for pin 5 with the Med 1 position.
It could also be an internal blower switch fault and that there is a short circuit connection between either the low and Med 1 setting or between the Med 1 and Med 2 setting. Hi should not affect it as it is a short circuit through the resistor anyway. With the plug disconnected from the resistor measure back toward the switch between the wires for pin 3 & 4 (light blue and light green/yellow) and 4 & 5 (light green/yellow and tan). and rotate the switch. There should never be a reading between the wires with the switch in any position.
Hi,
Does the blower motor run with the switch in the OFF position? If you leave the blower motor switched continually on you may not notice this.
''If so '' I suspect that there is an earth fault on one of the wires connected to either pin 4 or 5 of the resistor. ''If not'' then it may be a faulty blower switch
Here is a the blower circuit for a 2002 Dodge Dakota. Hopefully it is the same for your particular year model.
[image|914786]
With a DMM (Digital Multimeter - Ohmmeter function) remove the blower resistor and measure the resistance readings on the blower resistor module between pin 2 and pin 1 (should read 0 Ohms) then between pin 2 and pin 3 then 2 & 4 then 2 & 5 and see what they are reading to find out which one is failing.
I suspect that there will be no reading between pins 1 & 3. This is because this is the resistor which carries all the current when the switch is in positions low thru med 2.
However I am suggesting that if for example you had an wiring earth fault on pin 4 and the switch was on Med 2 then not only would you have the normal current flowing through the resistor connected between pins 1 & 3 BUT you would also have more current because of the circuit path available thru pin 4 (which shouldn't be there). This scenario is the same for pin 5 with the Med 1 position.
It could also be an internal blower switch fault and that there is a short circuit connection between either the low and Med 1 setting or between the Med 1 and Med 2 setting. Hi should not affect it as it is a short circuit through the resistor anyway. With the plug disconnected from the resistor measure back toward the switch between the wires for pin 3 & 4 (light blue and light green/yellow) and 4 & 5 (light green/yellow and tan). and rotate the switch. There should never be a reading between the wires with the switch in any position.
Hopefully I have not confused you with all this.