Why does my blower resistor keep going bad
Have replaced my blower resistor 3 times already in the past 2 weeks. What could be the reason it keeps going bad?
Is this a good question?
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.
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.
Hopefully I have not confused you with all this.
Was this answer helpful?
Trent, one of the biggest reasons for blower motor resistors to have shorten life is actually because of faulty blower motor drawing too many amps, some times melting wires/plugs, heating up resistors shortening their life. Many Dodge forums tell of this problem. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
Was this answer helpful?
Past 24 Hours: 90
Past 7 Days: 363
Past 30 Days: 1,550
All Time: 10,139