Four Seasons offers the following tips to help professional technicians resolve Chrysler’s flashing LEDs.

In many cases after the replacement of a battery, an HVAC control module or a door actuator, various button LEDs on the control module will begin to blink. This is due to a system requirement for actuator calibration to be performed. On 1996 to 2000 vehicle models, the rear wiper and rear intermittent wiper LEDs flash simultaneously. On 2001 to 2004 models, the AC and RECIRC LEDs flash simultaneously.

Here’s how to diagnose the problem:

1. To perform a test, set the parking brake, run the engine to operating temperature at idle, select the high blower speed, turn the mode selector to ‘panel’ so the AC compressor is off and move the temperature selector to full cold.

2. On 1996 to 2000 models, press and hold the rear wash and rear wiper buttons at the same time and hold the buttons down for five seconds or until all LEDs light up. After all the LEDs light up, the rear wiper and intermittent lights will begin to flash alternately.

On 2001 to 2004 models, press and hold the PWR and RECIRC buttons for five seconds and release. With manual systems, the power and recirculation buttons will flash. With automatic temperature control (ATC), the panel display of DELAY and the recirculation icons will begin to flash.

3. The test may take from 20 seconds to two minutes. On 1996 to 2000 models, if calibration is successful, only the rear wiper button will flash. If the rear wiper and intermittent buttons are still flashing, the calibration test was unsuccessful and further diagnostics are required. If the AC and RECIRC buttons are flashing, then the system has failed the cool down test.

On 2001 to 2004 models, if calibration is successful, the lights will stop flashing. If after three minutes the lights are still flashing, then calibration was unsuccessful and further diagnostics are required.

For more information, visit www.4s.com.