Chrysler Repair: 2002 Town & Country Blower Will Not Turn Off, hvac unit, socket 6

Question
I have a 2002 Town and Country Mini Van. The blower motor will not stop when I turn off the climate controls. As a matter of fact when I do turn off the controls, the fan blows even harder. Any regarding what to look for? Thanks for any help in advance!

Answer
Hi Mark,
I only have the circuit diagrams for the '98 van, but they may apply to your van. The 12V supply to the blower motor is present at one lead to the motor whenever the ignition switch is in the run position. The other end of the motor is a black/tan wire that goes to the fan speed switch. That lead either goes directly to ground or thru one or several resistors before it goes to ground which produces the various fan speeds. The 10 pin black plug on the rear of the control has all the wires that control the fan current pathways to ground. Pin 10 is the black/tan lead from the motor. So my suspicion is one of two things:
1. If you unplug the plug and measure between pins 10 and 6 of the module socket (6 is the pin that carries the solid black wire) you will get continuity (0 ohms) no matter where the fan speed knob is set. If that is so then the switch has failed and needs to be replaced/serviced because with the plug removed it should only show continuity when you have the knob set to the highest speed.
2.You will find indeed that the continuity is only with the fan set to the highest speed, but if you then plug the black plug back in and insert a pin in the tan/black wire on pin 8 and measure from it to a nearby shiny metal surface or to a pin inserted in the black wire at pin 6, that you will find there is continuity (0 ohms) regardless of where the knob is set. If that is the case then the resistor block which I believe is located in one of the air ducts of the HVAC unit (follow 5 wires from the control module black plug to the resistor block, or look around on the bottom of HVAC unit for a 5 wire harness whose color are tan/black,red/white,light blue,light green, and tan and the will lead you to the resistor block) has shorted out internally between all the wires and by an alternative pathway to ground. I say the last point because nominally the off positions should not be grounded but somehow the tan/black wire has gotten shorted to ground no matter where the switch is set. This has to be traced to figure out why.
I lean toward 1 as the more likely explantion of your problem.
Let me know if you find something interesting and how this works out for you.
Roland