Troubleshooting A MaxxAir MaxxFan Deluxe That Isn't Responding To Temperature Settings

Question:

Hi, I have a Maxxfan 6200K installed in a Promaster van. In auto mode it used to adjust fan speed based on temperature, but now only runs at highest fan speed regardless of temperature. Put in auto mode, then hit off button should reset to 78, then put back in auto mode green light on, held auto button for more than 3 seconds, hit + button to raise the set temp heard single beep with each push on the button, but no change despite presumably raising the temp above 90- its 80 in the van right now. Tried to reset by disconnecting from 12V source. No change. Thanks

asked by: Mark J

Expert Reply:

If your MaxxFan Deluxe Roof Vent w/ 12V Fan and Thermostat # MA00-06200K isn't properly responding to commands then the first thing to check is your power and ground. Make sure that you have a secure ground connection and check the voltage with a multimeter # PT89ZR to ensure the unit is getting a full 12 volts to properly operate. If the power and ground are both fine then it's most likely the circuit board malfunctioning and would need to be replaced with part # MA10A21276K. I would also ensure that the power wire is protected with a 10 amp fuse # SWC9538 to prevent any power surges from damaging the circuit board in the future.

expert reply by: Kevin C