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Joe Marconi

2003 Toyota Highlander: No A/C After evaporator installation

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Here’s a tip that might save you a lot of aggravation. One of my techs installed a new A/C evaporator in a 2003 Toyota Highlander. All went smooth until he pushed the A/C button on the dash when he got finished. The A/C button did not light up and there was a code for no communication between the A/C control module to the BCM and to the Dash Cluster.


Going thru the troubled charts and pin out charts led to a failed A/C Controller Amplifier. My manager was not ready to order the A/C amplifier, stating that everything was working prior. He felt that something had to go wrong in the reassembly process. He was right.


It turns out that there are two identical connectors, one for the vent control servo and one for the max air control servo. They are close to each other and interchanging them is an easy mistake. Switching the connectors was the fix.


Two things we learned: The tech needs a review on carefully marking all connectors and we need to be real careful when interpreting trouble flow charts.



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