I have what I think should be a simple question to get an answer for but I am having a bit of trouble finding an answer. I have an 05 R52S and I noticed I was running a bit warm. I got to noticing and appears I have no low speed fan happening. Then got to looking into the cooling fan resistor sticky above and that leads me to my question. My car should have a single plug fan (from my understanding) but my rad fan has both the three wire big plug and the small two wire pig tale coming from it. Only the big one is plugged in. If i turn on my ac and only on one level i get the rad fan to cut on for a couple seconds and then cycle off again (my understanding that is the high speed fan) now my quandary is how do i have high speed fan with nothing plugged into the part that should kick off the high speed fan (the small two wire plug) and do you all think the resistor fix will solve my issues with no low speed fan?

if I ohm out the low speed fan wires I show open there as long as I did it correctly.

just fyi if I jump power to the small plug terminals I hear the relay click as I would expect as well but with no power ever showing up to the fan. So I am a bit stumped at what I even have going on to begin with!

 

The big 3 wire plug controls both high and low speed (high speed power ,low speed power, and ground). Not sure what the second plug does but it's not directly related to the fan.

By everything you've described it sounds like the resistor is bad.

 

As you say, your fan should only have the big plug so it seems that you have the wrong fan. The two plug fan should have a relay in the resistor housing. The Detroit Tuned instructions for wiring the replacement resistor indicate a difference in the installation for one-plug and two-plug fans as well. So it wouldn't be surprising if a two-plug fan in a one-plug car resulted in the problem you're having. I don't think replacing the resistor will fix it.

 

Sounds like a bad resistor

 

WOW life is busy!

Anyway I fianally got a chance to take another look as I wasn't happy with my speedy look at my issue originally. I took a small strand a wire and hooked it up to my power from battery and the other one i grounded to the trans mount with a clamp. I then hooked the wire up to the terminals in the fan plug to just see if the fan would spin. High speed spins as well as low speed. That seems to tell me that the resistor is good. I have recently been driving around with my bluetooh odb2 adpater plugged in so I can see live data from the temps as the gauge is not accurate enough to get a good feel of what is going on. I can see that as long as I am moving hardly any at all my temps are great all the time. My family and I went through a drive through last night and while sitting I watched the temp as expected start to climb. As she hit the 221 mark the high speed fan kicked in and it cooled it back down very quickly so now i am going to try and figure out why my low speed fan is not spinning up at the 212 mark. So any common issues or random ones people have seen that I can double check in my quest for cooling!?

 

It is my understanding that if you do not have your air conditioning on, then the low speed fan turns on at 221 and cools to 215 and the high speed only comes on at 230 (or 231). If you have you air conditioner on then the low speed runs continuously as it is cooling the condenser.

 

I just went through this same issue just last week. I have a single 3 wire plug ('04 R53 pre-facelift). Easy DIY fix. You can read my thread:Can low speed fan be heard in stop and go traffic?
Although I can't take credit for this fix = There is very long thread here on NAM which I used the instructions to bypass my blown LSF resistor with an aluminum upgrade from: Mouser.com - ARCOL HS100 R33 J 100W resistor Works perfect!

I should have first prefaced this by saying; From what I understand you have a '05. After doing some research - The wiring description of the fan you currently have installed, is for an early '03 pre-facelift, R50 which came with the two plugs, large 3 and small 2 wire connector. I would almost wager (perhaps) your fan had been replaced at one time.
.
Yep - The temps you stated are correct. Mine works, (again) After I preformed the resistor mod.

 

All of this started a while back when I noticed I had a cracked overflow bottle and I kept loseing coolant and then that would eventually make things runn a bit warm. I picked a good looking resivior up from the pull a part to get me by until I replace with a metal tank and that seems to be working fine now. I also have now found that since I have been looking into things everything is working correctly now! I dont know if I had a stuck relay or a plug not making contact correctly or what but in my trouble shooting and cleaning up things the entire thing is doing what it should be the fan comes on and acts as expected if I go by the higher temps. So looks like it might be a failing part mixed with some mis information on my part but for now seems to be doing what it is supposed to be. Thanks everyone for the input and help with walking through yet another thing on "Tiny".