The unit will alarm when I turn on the Keurig, and often times it will shutdown.

I fully recommend this unit

This tells me the fan is simply connected to a thermal sensor and comes on when the unit is warm, like if the inside vehicle temperature gets warm enough to kick it in, even though the unit is turned off.

,, I don't know how good or bad these units are in

I hooked up the unit looks and works great

This unit does not drain when turn off which is

I took a chance on this unit based on price and review, I was in the market for a much more expensive name brand unit.