Cooling Fan Issue.

[refaller]

I just purchase my toy a 1999 SLK 230. When I got it, the duo-valve was broken leaving the heat on high the entire time. No big deal, it is winter. I fixed the valve and now when I drive through town after a trip on the highway, the temp gauge reads about 10 degrees high until I start moving again (unless I put on the heat). So when I pull over, I open the hood to see if the cooling fan is on. It was not. Eventually, it turned on, but was moving considerably slower than my other car fans. Would this be fan issue or the controller issue?

ref

 

[The_Eric]

Sounds normal to me.

Before you start condemning stuff, you'd better find the specs for the cooling fans and temps they come on at. Some cars will start one or more fans at a low speed, then ramp them up as temp requires.

 

[Audios]

Normally Benzs run above the 80 C mark dead center in the gauge. Sometimes almost touch the 110 area, but they were AMG, or the larger V8. Do you hav a single or dual fan setup? On the older benzs theres 2 fans that have a belt in between them, one frives the other. The belt would break and jam the powered fan, either causing slow operation or none at all. I also think they wouldnt overheat with 1 fan, AC operation suffers.

 

[refaller]

On the SLK Forums, everyone's R170 with the 2.3 liter supercharged engine runs at 80. Mine stays right around there until the town. The fan seems to be starting late (since it was well over the 80 mark- which is the middle of my gauge). There is only one fan and there is a fan control module as well. Supposedly, the fan sounds like an airplane taking off. Mine is not audible. I assume that means either the fan is not working or the control module is not giving it enough juice. I would also assume that the fan would either work or not, so at this point I am thinking it is the module. The thing is $200.00 so I was hoping someone would have experience. I will probably try and hot wire the fan and see how it speeds up- if it does then I guess I will check the voltage coming from the module. Don't know what it should measure and have not been able to find that out.

ref

 

[eljefino]

If you check the voltage coming from the module see to it you have a load on it, eg the fan motor. Use both a DVOM and an old fashioned test light, even a brake light bulb in socket kind of deal. (I use this for testing blower motors and the resistor pack leading up to) Jumpering the motor itself is also a great idea, use a fuse the amperage the system uses. If the motor is locked up or close to it it'll fry the fuse.

Sounds like a pulse width modulated module for variable speed and or soft start. IIRC Daimler "blessed" my (short lived) grand caravan with one of those.

If you're running warm and the fan is on you should be able to feel it throwing heat, generally standing outside the driver's door by the A-pillar if not leaning over the engine.