Cooling fans in 2002 CLK 55 AMG
The two auxiliary fans are behind the grill, and behind a second plastic grill, but in front of the condenser. Open the hood and look where the grill would be with the hood shut. You’ll see a plastic grill. Look closely and you’ll see two fans behind that. The secondary fans can be tested as follows - with the car off, insert the key and turn the ignition to the second position (where the dash lights are illuminated). Immediately press and hold both climate control "Auto" buttons for about 10 seconds and then let go - both black auxiliary fans should turn on. If only one fan spins, you may have a problem with the fan itself, the fan relay or a circuit to the fan. The fan will normally turn on at approximately 103 degrees Celsius. It will shut off at approximately 98 degrees Celsius, but doesn’t run with the car turned off.




There is an axillary fan control unit that works with the AC and engine temp. (supposedly behind the left headlight).
The engine viscous fan clutch should carry the heat from the engine in most climates without the necessity of aux electric fans. Other problems in the cooling system might exist.
More diagnostics might be needed to get deeper.
My fan clutch is on the way out and the electric fans run maintaining around 85^ ~ 90^ C in extreme Florida summer heat.
100^ C is boiling.
Gator





