Well I did a pretty thorough search for me and can't quite seem to find what I am looking for. My 1994 SL 320 has 74k miles, when I ride at lower speeds (ie.30-50mph)with the ac on my temp guage is creeping up to the 120 level even with high speed fans engaged. When I shut off the ac and turn on the heat for a short time the temp will drop to it's usual 96-98 running temp reading. At first when this happened I checked fuse at position 7-fine, Fused relays green 30 amp had a blown fuse, blue 15 amp fine, I replaced the blown 30 and upgraded the blue to a 25 from advice in a post left by ArtDalton. Fans work no problem now but still have the same bug. All surface temps by my infrared thermo which is Fdegrees are within 5 of each other, at full hot top radiator where dash reads 118 I get 204/converts to 96C am I too anal here or is my temp sender gone. Since this happened and all fuses were replaced I drove it again same results and a blown 30 amp fuse, also no high speed fan op at all during that time I have a cool harness 92 which is not installed at this time until I straighten this mess out. I am attaching a picture of my relays are these in the right positions? Relays are closest to the firewall in my car.
Thanks much Keith
Fan Clutch replaced 7/06
Complete engine Wiring Harness replaced 10/06
head gasket replaced 10/06, with thermo kit at that time
Aux Fan Harness replaced 7/07

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Test drive after replacing temp. sensor, blew another 30amp fuse, could this be a relay issue? BTW my car is an early 2 plug thermistor sensor model.
Thanks, KD

I will post a reply to my own thread again with today's test results. Today I was able to find a relay diagram on my alldatadiy.com website link and realized that my relays were in the wrong position for my car. The A position is closest to the firewall in this model, previously the B position held an unknown 30 amp relay, the C position held the blue High speed relay which is 15amp fused, the D spot was held by the green 30amp low speed relay also fused. So I changed positions to be correct and made sure my relay fuses were allright. I upgraded the blue to 25amp, and left the green at 30amp. So far (one day 89F top temp)no overly high temp to report, I also changed my temp sensor yesterday. After checking my relay layout I will check my horn function tonight and continue to check my temp as the days go on. As always any info supplied is gratefully accepted, after all a diy is a diy not a pro.
Thanks,
KD

Continuing the saga, after all that I had done thru this repair process I returned from business to find I had blown another fuse and was still not thrilled with my temp situation, after a message from Art Dalton I re-examined my relay diagram and realized that I had not placed them properly. I moved them, upon start up and further check I found my aux fans were indeed blowing the wrong way creating a very hot space where the radiator and AC condenser live. Pulled apart the nose of my car to find the harness I had replaced by my mechanic only to find that it was installed as it should be. After digesting this for a few hours I decided WTF I will snap the directional pin off this harness where it attaches behind the LF headlight and flip it over if it doesn't work he will get the car back anyway. Lo and behold the fans blow correctly and my temp situation is tremendous a constant 82-98 on the dash scale so far no blown fuses either. Wierd problem as when the car was at highway speed and enough air passed thru the radiator everything seemed fine. Lower speeds the temp went straight up, I think I blew relay fuses from the load of both fans working opposite each other. I will monitor that closely, I re-installed Jim Forgione's ch92http://pages.prodigy.net/jforgione/MB_S500.html and it now works the way it was supposed to keeping my car's temp down to very low levels even here on a 95F day with high humidity.
Regards, KD