Thought I might get some interest with this subject....

I am trying to find out why my car, 92 300D, is running 90-100C. So far I have drained and flushed the radiator-clean fluid, no rust, and replaced the thermastat. I noticed that when I ran the defrost that only one aux. fan came on. Is this right or is one not working? If both should be working, what is most likely the problem? Fusses are good. Thanks for any help.