operation of cooling fans R129 500SL
 

can anyone explain the opereation of the cooling fans mounted in front of the radiator, are they for A/C alone or do they aid in the cooling of the engine. Mine cycle occationally after startup and then shut off, but I haven't seen them come on after that????

What Year??

operation of the cooling fans R129 500SL 1991
 

Sorry about that , 1991's the year

Aux fan operation on THAT model goes like this....

IF the ambient temp is BELOW 15C the low speed fan comes on when the A/C refrigrant pressure reaches 20BAR...high speed at 107C engine temp

IF the outside temp is above 15C & the car is below 25mph then the low speed fan comes on any time the compressor is engaged.
High speed still comes on at 107C engine temp

Dear Doc,

What is the expected behavior for a 1994?

Mark