A MaxxFan Roof Vent w/ 12V Fan Works While Off-Grid But Does Not Work Properly When on Shore Power

Question:

Recently purchased and installed this 4301K MaxxFan on our 1987 Bigfoot B17. Great looking unit, easy to install though it wasnt clear which dimples required screws. Works just fine when off-grid 12.7V - battery fully charged, but the minute we use the 120V hookups 14.02V charge voltage, not even going to 15V pressing the power button gets the fan to spin for about 1-1/2 seconds before it shuts itself off. If we run the fan and then hook up to 120V the fan continues to run and we can adjust the speed just fine, but the moment we turn it off we cannot get it to do anything more than the 1-1/2 seconds thing again. Doesnt this fan accept charging voltage? Quite ridiculous if we cannot use the fan while hooked up! My question is: does the MaxxFan operating voltage range seriously not allow for charging power, common to all inverter systems meant to simultaneously charge the battery and run the 12V system?

asked by: Chris

Expert Reply:

The MaxxFan Roof Vent w/ 12V Fan # MA00A04301K needs a voltage no higher than 13.1v. Anything over 13.1 can cause the fan to not operate correctly or at all.

So to answer your question. No, the MaxxFan Roof Vent w/ 12V Fan # MA00A04301K does not allow for charging power. I also agree that it is a little ridiculous, considering most RV's are going to have that type of charging/inverter system.

expert reply by: Scott S