overheating in a 1988 Bmw 735IL

My car over heated and and blowed the fill tank, I replace the fill tank and put in a new thermstat. also replace the thermo-switch on the radiator. t
The car is still overheating, but I did notice the aux fan is not coming on and passenger side of the radiator in which I installed the thermo-switch is not getting hot. If some one could give me some sort of insight on what is going on I would be so ever greatful. My email address is kamira3591 @live.com