Lexus Repair: heat &ac fan, voltage output, fan motor

Question
my es300 has a heat & ac fan that changes speed seemingly on its own the display shows a constant speed but the fan will speed up and slow down very quickly . most times it will work normally. this has been going on for over a year

Answer
Hello Greg, This can be caused by a couple of different things. A fan motor problem do to age and wear, or a sensitivity to fluctuation in voltage do to engine rpm changes or alternator voltage output. Hard to say which. I would not worry about it at this point. If something is wearing out you will know eventually.