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Automatic Temp ControlPosted 9/3/1997By Tom Vadnais
1993-95 Chrysler Concord, New Yorker, LHS, Dodge Intrepid and Eagle Vision.
A call came in from a frustrated shop owner-technician with a case of "you touched my car" syndrome. He had changed the oil and now the customer claimed that the A/C did not work properly. After going through the preliminary checks, the technician discovered the automatic temperature control was not changing temperature when commanded to by the panel input. Still unable to diagnose the problem after exhaustive testing, he called his favorite hotline. Together we went through some basic checks and discovered the temperature control servo motor was not operating. Since he didn't have a scan tool capable of getting into this system, we went through system calibration by pressing and holding the Floor, Mix and Defrost controls at the same time, with the vehicle running, until the display started to flash. The system then calibrated all of the doors and went into diagnostics. No fault codes were found. During the tests, the technician said the system seemed to be working so I had him run through all the different modes and temperature settings and, indeed, it worked perfectly. The doors had been out of calibration! When I asked the tech if the battery had been disconnected for any reason he replied, "Doesn't everyone routinely clean the battery cables as part of a LOF service?" Actually, I don't think everyone does. But because of this technician's good work ethic, he ended up with an unhappy customer and extra work for himself. The moral of the story: Every time the battery is disconnected on these vehicles, the automatic temperature control needs to be recalibrated.
Ford One-Touch Four-Wheel DrivePosted 9/3/1997By Jeff Boskowitz
Looking back to when I was growing up in a small town on the shores of Lake Superior, I remember playing a game called "Captain, May I." The object was for one person to be the captain, who secretly selected a certain objective. All other players had to come up with ideas to reach these goals. If you asked, "Captain, may I go to the basement?" and he was satisfied with all the actions around him, and that the end result of permitting this request would help him reach his goal, he would grant it. Sometimes he would get nowhere and a new captain would be selected. The game would continue until a captain would reach his goal and win. The same scenario can be applied to the Ford one-touch four-wheel drive. The general misconception we see when fielding calls on the "one touch" or "shift on the fly" four-wheel drive system is that when the 4x4 button is pushed, an electrical connection is made from the button to the shift motor. In reality, a game is being played. The heart of this system is the shift control module. This is our "captain." When you push the 4x4 button, you are actually sending a signal that asks, "May I have four-wheel drive?" The captain then looks at various switches and sensors to see if the request is a reasonable one. If so, the shift is made and, if "satisfied with the results," the module turns the 4x4 light on. The other "players" are the transfer case motor position switches, the transfer case speed sensor and a neutral input switch. All the players must have a valid input into the game or the captain won't grant the request. The bottom line is that with a good wiring diagram in hand and a general knowledge of this system, you should be able to win every time.
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Copyright (c) 1996-2008. Automotive Service Association. All rights reserved.
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