Sorry, as I know this type of question has been asked over and over. But I want to make sure I am checking everything. Short. blend doors went at 5000miles, fan motor stared going on and off (Changed the little thing by the motor). Then changed the ing switch. All was well for a year. 2 summers ago, lost my A/C compressor. Have replaced compressor, condensor, about to put on new dryer and liquid line. Its been cold here in the Atl area. now fan has quit once more. I bought the switch from O-realys. Its a dorman. Should I have purchased a Mopar part? I am almost tired of this truck (06 megga 2500 CTD) I am a Mopar man all the way, but am realy tired of the problems this truck has given me. I Have had many Dodge trucks. But this is the lemon of the decaide.

 

Hate to hear the bad luck you have had. As far as the switch, you should be fine. I don't see the Mopar one being being and better. Just more $$$ to buy it

 

The fan gets + from the ignition switch any time the key is on, and gets - through the fan speed switch either through the resistor block (on lower settings) or directly when on high.

There have been threads about charred wiring and/or ignition switch relating to the fan motor not running or not shutting down when the truck is turned off.

There was also a thread where a guy's fan quit. Volt meter showed power at the fan plug when turned on, but new fan motor didn't help. It turned out he had the charred wires/ignition switch socket. Apparently it had a good enough connection to show voltage on the meter at the motor's plug, but that went away when any load was applied to the circuit (like when the fan was plugged in).

 

when you open your HVAC system to atmosphere you are suppose to replace your accumulator/dryer and orifice tube at the same time. This should have been done when you replaced your compressor. Also, as a side note, when you do this, put a inline filter on your system. (just before it enters your condenser behind that plastic cover) if for some reason you have a catastrophic compressor failure, it will catch all the debris prior to entering your condenser saving your system.

 

I have not charged the system. Seems that at the time I was doing all the work of changing the conden and the compressor, the liquid line was no where to be found. I have not tryed lately. So after the fan fix, It will be my next project. Also, I bought a after market condensor, but I am thinking of replacing it with the mopar unit before I complete the job. Last time I checked the wiring to the switch, it looked fine. But I will have to check it once more.

 

I wanted to say, "Thanks" for all the help. I found the problem today.
got the meter out and started checking the resistor and power. when all turned out fine, I broke out the unaversal tool. (A hammer) and knocked the crap out of the fan. And it works. I guess I need a new one.