i recently had my fill resevor burst and had it replaced car still overheats on 2003 BMW 325i

so i went online to review problems with overheating and followed the procedures on how to determine the problem, so i turn the ac on full blast to see if the fan turned on in which it did not looked as if it wants to turn. how do i determiine if its the motor or the fan relay switch?

Asked by for the 2003 BMW 325i
Mine did the same thing on my 528i.The problem with it was the fan clutch being faulty.It would get hot at idle when the fan clutch is most needed to keep the fan blowing hard.Replaced fan clutch and fan (had cracks in it) replaced reservoir,problem solved! Not saying this will fix your concern,but it is relatively easy to check.