I have a 2003 mcs . My car is fine when driving but heats up when in traffic. Can anyone tell me the fan sequence. (I.e when the low or high speed fan comes on. Does the low speed fan come on regardness of the AC? If so , at what temp? And my AC does not blow cold air when non of the fans come on. Thx ahead ..

 

Thermostat

Thermostat begins to open at 89-92° C (192° F - 198° F) and is fully open at 103° C (217° F).

Expansion Tank Cap Cap pressurizes the system to 1.1 bar (16 psi) at which point the cap valve will lift to relieve pressure.

Cooling Fan

Radiator Fan is a nine bladed fan measuring 400mm in diameter, driven by a 350 watt motor controlled by the EMS2000.

Low speed is switched on at 105°C (221° F) coolant temp and off when the temperature drops to 101°C (214° F).

High speed is switched on at 112° C (234° F) and remains on until the system coolant temperature drops by 4° C (7.2° F, so @ around 227F) at which point the system will revert to Low Speed.

The cooling fan will also operate on Low Speed when the Air Conditioning is switched on and system pressure reaches 8 bar (116 psi). Should the Air Conditioning system pressure rise to 18 bar (261 psi), the fan will automatically run on the High Speed.

 

Your low speed fan resistor is likely toast. There's a sticky over in STOCK PROBLEMS on this.

 

That's great info. Thx

 

And on a 2003 (Till Dec 2004 actually) the entire radiator fan (both modes) can be disabled when/if the power steering fan jams...blowing a 5 amp fuse in the drivers compartment... De-powering the relay that runs the radiator fan....
In 2005, and in all "modified cars", under a nationwide campaign, many cars were rewired...
The fastest way to tell...look at the plugs by the radiator fan...an oval 2 prong plug is the PS fan power supply.... On a modifier car, it is usually cut off, or left unused....if plugged in, it is the sighn the car is unmodified....