Auxillary Fan Question 72 450SL
 

My manual states that it should come on at 212 degrees F
but mine cranks up at about 175 degrees. I am beginning to think my temp gauge is off or my senders are bad, before I start replacing willy nilly I thought I would ask who has been there done that
Basically, temp gauge stays steady at 175-180 degrees , fan comes on when she gets near top temp ( 175-80) so basically it runs alot. Of course it is bloody hot here, I am not running AC, I prefer top down.
any ideas? perhaps just normal for 35 year old car????

Ron, check your temp with an IR thermometer perhaps right where the sensor that looks like this is:
http://img.eautopartscatalog.com/live/G503012319BEH.JPG

If it's not 212 or higher, the sensor is bad. They can eventually wear with age, turning on too soon. If I don't have a spare you can pick up a new one, but I think I owe you for that hood latch still so if I can find a spare (which I won't have time to look for until MAYBE Sun PM, as I'm going on vacation this weekend), I'll send it your way.

thanks Tom, I think that may be my issue, everything else seems OK, i figure I will change it out when I do the coolant flush. Let me know if you find your "spare"

I have found 3 sensors Ron - but not 1 is a 212 switch. I'll look in my spare parts bin but I doubt I have it there. I need to check the bin when it's light in my garage!

I see there are for sale out there replacement fan switches that run the fan at 90 C which is close to where yours is coming on. Does it have a temp stamped on it & could it possibly been changed out by a PO in the past? Just a thought....

perhaps that is the case.
I have decided to change mine out, don't stress tomguy, just thanks for looking.

aux fan
 

why worried it kicks on too soon? I am mad mine kicks on too late. seems to me early is better?

perhaps, but its not right, as you can tell by my many posts, I like things the way they are suppose to be:dizzy2: