The air conditioner selector switch in my 2002 2500 does not turn the blower fan to the high position when you select "Max AC". It quit at about the same time that I had to service the system with R134. Could there be a relationship there? Is there a relay that controls the fan in the Max position? If so where is it located. Will it show me in the Dodge service manual how to remove / check the switch. I probably should buy one as my Haynes manual is not very specific. Thanks in advance for any help provided.