When I got my '89 300se back from a service, the dealer left a little note in the car saying the auxillary fan was not working. Sorry for being stupid, but what does the auxillary fan do? I was a bit concerned yesterday, I went on a 350 mile drive, and when I hit heavy traffic and was stationary for a while, the engine temp hit just under 120c and was almost redline.
Also, before I took my car in for a service I noticed there was a lot of play with the steering wheel before it affected the direction of travel, and it was a bit dodgy at speed (if felt like it was drifting left to right, especially in medium/high winds). The dealer said I need a new steering box. Are these cheap, do i have to go mercedes, or can I go for and OE brand?

Thanks for all you help

Oliver