Hi,

I've searched through the form for the specific problem I'm having with the low-speed fan on my 2006 R53.

The high-speed fan kicks in OK at 105oC (220oF), so the car never overheats, however there is no power to the low-speed resistor prior to this.

Actually my resistor has been removed a while ago and I simply put a wire short in it's place (so the fan should run at full speed).

My first question is at what temperature should the low-speed stage of the fan kick in? I know the OEM themostat is 91oC (195oF), so I'd assume the low-speed fan would kick in to maintain this temperature.

My second question is to do with the wiring of the low-speed stage of the fan. According to the Bentley manual the fan motor is wired as shown below; I'm wondering if this is accurate.

 

Low speed set point is 221 and the high is 234. You might not have power to the low speed but the high speed is acting like the low speed.

Moving you to the Stock Problems/Issues as well.

 

Thanks and apologies for posting in the wrong place.

I'm beginning to think that I've got the fan speeds mixed up, but I think it's strange that the low-speed set point is so high at 221 (105oC). This is what is specified in the Bentley manual, but I'm thinking this couldn't be correct.

Surely the fan should try to maintain the engine temperature closer to the thermostat setting of 195oF (87oC). To allow it to increase 20% more than this does not seem correct.

 

No apologies required, rather have you ask the question than ask none at all.

The cut-out point is 7 F below both high/low cut-ins.

 

Still seems strange to have the engine allowed to heat up so much above the thermostat setting of 91F.

So the engine is allowed to heat up to 105F and the fan cools it down to 98F (which is 8F higher than what I would expect to be the optimal running temperature).