Chrysler Repair: Chrysler minivan automatic door locks lazy, chrysler minivan, positive temperature coefficient

Question
In my 2002 Town/Country the automatic doors only work when its warm outside. When button is pressed while cold the door unlook, makes a noise, but doesn't begin to open. My rear hatch has stopped working in any kind of weather. It beeps, but doesn't open. What's the problem(s)?

Answer
Hi Charles,
I suspect that it is either the PTC (positive temperature coefficient) device (similar to a fuse) in position #3 (9 amp) located in the horizontal row just below all the 4 plugs of the fuse box under the dash. It might be putting thru too low a voltage to operate the door lock relay. There are also three relays just below the PTC that have to have good conductivity across their internal points to pass along the voltage to the door lock actuators. If you have a voltmeter you could check the output of the PTC and then the relay outputs. Or try substituting one of the other PTC's for the door lock PTC and note if that improves the function. I am working with the '98 manual so I may not have the correct # of the PTC but check for any labels on the box. I can tell you which pins on the plugs represent the outputs of the relays if the PTC seems to be OK.
Roland