The temp finally rose to 81° in the past 2wo days = My comfort zone.
Both days I've been stuck in heavy stop and go traffic. While I kept an eye on my oil temperature gauge I noticed it peaking, @125°C (258°F), Not dangerously high but higher than normal that I've noticed in the past. I don't think I've ever heard my low speed fan kick in under similar conditions. I didn't this time either. High speed works fine and usually kicks in intermittently after long drive/engine idling while stopped/parked and/or steady for 5ive min after shutdown. I can also usually tell as my Volt gauge drops to 12.5-13v.

Does the low speed fan kick in during heavy traffic? I've never heard the (low) fan come on or see a voltage drop.

I don't run the AC and Water temp was normal/half way mark.

I found a video on how to test low and high and will do some testing this weekend. - Just curious.

 

I never hear my low-speed fan turn on the R50 or R52.

 

125c is high. High fan should come on at 112c and push temps back down

inpa will tell if low speed fan on. You can get a visual from engine bay. Low speed should come on at 105c

cant hear low speed fan in traffic

 

Agree.
Tested low & high this morning. Resistor is shot. High works fine. NO low speed.
Interesting; as the Water temp stays normal but oil temp rises.
Never owned a water cooled car before. So this is new to me.

Timing is also interesting as I just changed the oil and filter w/5w30 (@ my regular 5k interval).
I bought a brand new fan 3 years ago. Still in box/never installed. I might consider pulling it's resistor - R&R to my existing OEM fan.

 

Paste the above for a resistor replacement; les than $20

 

Well, I was thinking about going this route....

Since "simply" R&R the resistor would still require front end service mode. At which point I might a well replace the fan entirely....Just to have it go bad again in the future.
I also kinda like the thought/don't mind the high speed running opposed to low.

 

So that would be high speed kicking on at 105 C? Interesting. I have the older 5-wire fan so wouldn't work for mine. Replacing the resistor wasn't too bad, except for fitting the relay into the housing but that's only necessary for the pre-2004 fans.

 

If you can pull the fan housing, you can use this one - https://www.ebay.com/itm/28446915965...evt=1&mkcid=28 - as it's a much better version than the original style that came with the fan, and some of the replacements you can get. I did this on my GP and my older '03 and it's worked well. Worth the little bit more money as you won't need to replace it ever again.

 

Yep - Another stoopid noob question - Here we go....

While I am seriously interested in performing this LSF resistor mod as pictured; I also understand that the LSF will run @High speed (as opposed to Low). I don't think I'll have a (personal) problem with that.
My question(s): Is it possible to adapt/solder a rheostat, potentiometer or some sort of (dial) voltage regulator in line between the modded Low speed wire and the resistor? My thought was; Being able to control the power/speed of the fan by means of a physical dial I could adjust up or down?


Is it possible, simple, (feasible)?
If so; I'm about to order an Arcol (HS100 33R J) 100W .33ohm 5% resistor - What specs would I look for when sourcing a 12V "potentiometer" (dial)?

I appreciate your leniency with respect to my novice electrical expertise and limited vocabulary in these matters.

** ramjett 77 & Soul Coughing, Thanks for the links to the resistors. I'm definitely going pick up a spare to have on hand.

 

I can't remember exactly how I did my '05, it's in a thread from years ago.

But high speed fan kicking in at the low speed temp was the result, and it didn't require a resistor, just some simple rewiring.

In all honesty, the low speed fan engineering is nothing more than a convenience for the driver, it's basically there to limit the noise from the fan during minor engine temp fluctuations.
It's both over and under engineered, OVER because of its reason for existing, UNDER because of its use of a resistor instead of solid state circuitry to control the fan speed. The heat generated by the resistor is the entire reason they had to use such heavy gauge wiring for the low speed side of things, just not that great of a design.

I've been running fan at full speed only for years, no issues at all, just a little more noise when stopped in traffic or a drive thru.

 

Today - Mid afternoon, while driving, my oil temp rose to 115°-120°C. The HSF never came on.
As I'm awaiting on delivery of the 100W resistor I did some further testing.
As before, I ran one lead from the positive battery terminal, the other grounded to the chassis and connected to the posts on the Cooling Fan plug posts/terminals. What I already knew was the LSF (small red wire) post did not respond to either lead from bat and/or grounded lead. However; What I found interesting was if I connected the pos lead (from battery) to the HSF (large red wire) post and the grounded/chassis wire to the black wire post on the fan plug; the LSF comes on with no problem.
If I reverse/switch polarity/lead wires (vise versa) the HSF kicks in wildly. See images below:


Both fan speeds work perfectly. Engine compartment fuses look good. I don't know (can't tell) if the relays are bad or have anything to do with the problem.
When plugged in as normal, Still neither fan comes on at temp.
I'm baffled.

 

Better double check that,
if I remember correctly the larger wire is the low speed wire, not high speed.
The larger diameter wire is to combat the heat from the resistor that "chokes" the voltage to run the fan at the lower speed.

 

Well, according to the LSF resistor wiring mod pic (post #6) indicates that on the fan side; the smaller red wire leads to the LSF. That wire that traces to that post does nothing when power or ground is applied.
I'm assuming the small red wire is connected to the blown resistor.
My apologies for belaboring this thread due to my lack of knowledge/ignorance.
Nonetheless- I will move forward with the resistor mod when I receive it. Seemed to have worked for others.
Thanks.

 

I think the basis of this is all wrong. I still learning too, but I'm pretty confident the fans are tied to COOLANT TEMPS not oil temps, as posted by the OP.
The low speed fan comes on when the coolant temp reach 105*C and go down to 90 something, and then hi-speed at if it's extremely hot 112*C.
and I can't hear the low speed fan normally driving, unless I'm testing the system, intently listening with the window down and watching the gauge on Torque Pro.

I don't believe it is tied to oil temps, because my system has been in sync with coolant temps like clockwork. My car is an 06, so facelift.

Doesn't the manual trans have an oil cooler? Maybe something could be up with that?

 

Quick thought, are you reading coolant temp off the dash gauge from chrono pack or through the OBD seeing the exact degrees? They will read different because the dash gauge lies (or so it has been documented from chrono pack owners). It will stay in the middle mark until it actually goes over 112*C, which is far too late to be a good gauge! Your highspeed could be kicking in because your lowspeed isn't cutting it for some reason. Maybe oil cooler not working or blockage and overworking the system?

My car never goes into high speed fan, its very rare and its an alarm for me to inspect the cooling system. Unless its like 105*F+, I'm trashing it and immediately parking then it may or may not come on.

It shouldn't even ever come on in idle in 81*F weather because the low-speed should be adequate (I know, I get bored in long *** drive thrus and monitor it). I would say look at the oil cooler. I don't have an oil temp gauge, so unfortunately I can't correlate normal coolant temps to average oil temps. But you say they are higher than normal and I would follow that breadcrumb. Long drives and idle should not be activating high speed fan. High speed fan = boilover imminent, blow all air possible to save the car lol.

One thing is for sure, if you hear your high speed often, something is wrong. We just had a 90*F weekend here and after a spirited drive my parking temp was 93*C and only rose to 101-2*C not even needing the low-speed. Just to give context to how it should normally work.

 

I could be reaching, but worth checking that oil cooler.

 

Success!
Completed my Cooling fan resistor mod this morning. Happy to report that everything is as it should be!
Although, I did have trouble sourcing some wiring materials from 3 different auto part stores (Advanced, AutoZone & Orielly). Neither had shrink tubing...(Hence, the title of this recent post).
I chose to go with 12guage wire and soldered connections via pencil torch and iron. I chose a preliminary/test placement for the 100w resistor = outside of the main engine compartment to test how well it would stay cool. This thing gets blazing hot!!!
Below is the spot I chose for this experiment:




My logic has me thinking; The resistor might stay relatively cooler while in motion..... Will see if my novice logic passes or fails as if (or not) it gets a sufficient amount of air circulation from the grille in this particular spot
Thank You so VERY much for the insight and kind contributions from the talented NAM members for this thread: Low Speed Fan Resistor.....

Thank you for that, Ninima.
Point well received with respect to correlating speedo water temp with OBD. I don't use my OBD far enough for real-time diagnosing - As I should. ...Mostly used to read and clear codes.
Ran my OBD and water temps matched almost perfectly within 2-3° . Mid point on gauge - OBD : 91 - 95° @ normal op temp.. As far as Cooling fan is concerned my suspicions were correct. LSF resistor was shot. Having been an air-cooled engine car owner (as long as 38 years), I understand the importance of maintaining engine's safe operating temperature which by only means of adequate air circulation. Forced or otherwise. If radiator fan fails; the oil/engine temp will be adversely impacted as well. Even dangerous.
After the aforementioned mod/fix the fans work as they should. A 25mi drive in the city; proved oil temp only peaked @ 110-115°C. Water temp stayed normal between 91-100°.
Air is life giving.

 

I am glad you figured it out and very nifty resistor placement! I might have to borrow that idea when my LSF resistor dies.