HVAC Air Flow Switching to Defrost When Accelerating on Dodge D150

Submitted by Vehicle Owner · May 29, 2025

Published by RepairPal

Problem overview

The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops. There is also a revised vacuum check valve available to address this concern.

4 people reported this problem

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Dodge D150 vehicles with this problem

4 model years affected

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