Chrysler Repair: fan blower on high only: ATC unit, chrysler concorde, 1994 chrysler concorde

Question
I have a 1994 Chrysler Concorde than has developed a problem of the high speed fan being on constantly. i can't adjust the speed or turn it off. The Dash board unit was replaced 4 or 5 years ago. Running the ATC diagnostics reveals no errors as it works through its routine.

Do I need a new blower control module as the Control Panel seems to be OK. Any other suggestions before I purchase the blower control module ??

Answer
Hi William,
This is a common type of malfunction. Your problem is a malfunctioning blower power module. It is the device that produces the 14 different voltage levels for the different speeds. It is only putting out one voltage no matter how you ask it. It is located in the duct near the blower motor. Remove the lower edge (access panel silencer duct) of the panel on the right side for better access). Just follow the blower power wire to its other end at the module and unplug it. Then remove the 2 screws that hold it in the duct and replace it. It may be possible to repair it if you have some skills in electronics, but if not you can either get one from a wreck or from a dealer (new). You need the power module, not the "resistor block", which is a simple 4-speed device used for the non-ATC type control units. So be sure to get "power module".
Roland
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