i have the harley fan on my current ultra with sidecar - i had a harley fan on the road glide with sidecar before that
the fan comes on 4 or 5 times every hot day [was on half a dozen times today, so far and i have another hundred miles to go] and i have never had a problem with either of them, they have not failed, or broken, or quit, or whatnot.
whenever the engine is hot the thing runs, when it cools down it quits. i ride a LOT in the metro area and when i get stuck in stop and go traffic the fan runs most of the time - i also have a remote oil filter and cooler mounted on the right crash bar near the sidecar body - lots of air flow & no oil gets on the bike during oil changes.
i do know that folks with se air cleaner back plates have problems because the sensor cant be put in quite the right place - but if you get the sensor right it works. [sensor has to be 1/16" away from the head fins]
tp