thermo switch - fan kit.

2010 fs570
i commute in 35 degree plus heat (peak hour traffic), so i fitted the fan kit, that thermo switch kicks in way too late i reckon. does anyone know if there is a switch available with a lower threshold temperature?

There sure is, and for much less than KTM charges. The 'accessory fan switch' for the '04 BMW 318i is interchangeable with the KTM sensor and is available in several different heat ranges. I prefer the 95/90 C unit. You can pick one up or order one through your local auto parts store. Note that the current stock KTM sensor is rated at 100/95 C while earlier KTM sensors were rated at a too low 85 C.

thank you.

so i just need to ask for a bmw 04' 318 thermo switch?

from which part of the car?

As mentioned, it is the Accessory Fan Switch for the cooling system.

Here's the part from Napa.
http://www.napaonline.com/Catalog/Catal ... 81982&An=0
It fit my 07, are the threads the same on the 10?
I tried it for a few rides, fan came on way too early. Went back to the 95~100 switch.

I bought a used '10 FE 450 in early December. Several weeks ago I purchased and installed the Husaberg Fan Kit. I havent been able to ride on the trails yet here in Colorado due to snow and cold weather. Nonetheless, after installing the kit and running the bike in the driveway to see how long it takes to get the fan to turn on, I felt like it the OEM switch did not turn on soon enough (bike had to get real hot). I found a replacement switch that turns on at 95C and turns off at 90-91C (at least that is what is marked on the actual switch. I think the KTM/Husaberg OEM spec is something 100C/95C or 102/97C.

I had read here or elsewhere that you can use the fan switch from an '84 BMW 325E. I have recently ordered a number of items from www.rockauto.com and been really impressed with their cheap pricing and their quick delivery. So, I went looking for what was available from Rock Auto. They list over a dozen stock switches available for this model with a couple special order ones as well.

If you go to their catalog (www.rockauto.com), click on start button, click on BMW, 1984, 325E, Electrical Switch & Relay, and then choose Radiator Fan Switch to see the available listings. The prices of the switches range from $4.45 to $24.79 for the stock items (with various brands and on/off temperatures). Be sure to get the TWO prong temperature sensor. They incorrectly show 1 item with a 1 prong connector among the choices.

I ended up picking up the Beck/Arnley 2011310 switch which is a 95C/91C switch. Cost was $13.65. Shipping to my zip code (Denver, Colorado) was $1.61. The Beck/Arnley 99C/95 switch (2011312) is $5.75 with $1.64 shipping.
There are several other brands that you may like better with varying temp specs (and some are hard to tell the exact specs unless it mentions in the description).

Here is the link:
http://www.rockauto.com/catalog/raframecatalog.php

I can assure you the Beck/Arnley switch I purchased (2011310) is an exact fit/copy to the 2010 OEM switch with the exception of lower on/off temp.

FYI....I know it sounds like a sales pitch above, but I have no affiliation with Rock Auto. I have used them about 5-6 times for auto parts and have been impressed every time with the speedy delivery and what seems like reasonable prices. But, I didnt scour the internet looking for the absolute lowest price. For all I know some other places have it cheaper, but I wanted to offer this one up as an option.

This radiator fan switch is also not unique to one model BMW. They list about 21 different BMW models that it fits all with multiple years. I dont believe the year/model listed earlier in this thread was one of them, but I am not absolutely sure.

Just installed the fan on my new 2011 FE570 then let the engine idle and waited for the fan to engage. The radiator coolant boiled over and no fan engagement. Checked the fuse - good. Recheck the simple wiring - good. Then disconnected the thermo fan switch connectors, held them together to bypass the thermo fan switch to complete the circuit and turned on the ignition - nothing.
Question: what next?

Check to make sure that you have 12V to the fan thermo-switch. If the fan fuse is good and you have 12V to the thermo-switch and the fan doesn't run when the terminals are shorted something is wrong with the fan. Does the fan blade turn freely?

Check all connections and draw a diagram and make sure it makes sense.

Buzz it out with a meter and make sure you have +V where it's supposed to be hot, and ground where it's supposed to be ground.

Make sure nothing's blocking the fan from turning.

If it's getting juice, it could be a bad motor.

Thanks, Chas and Oldnewbie. Fan blades turn freely. What do you mean by +V? The electrical connects seemed pretty straight forward without any unplugged connectors.
Ordering a 95/91 C fan switch through Rockauto. Hope this cools things off.

Could someone let me know what size the fan is? Spal makes radiator fans that look just like the fan from the kit, they have a 4" a 5.2" and 5.6" radiator fans. It would be cheaper to wire it up myself then to buy the fan kit.

Jackrabbgit, the fan is roughly 4 inches in diameter.

OldNewbie, if you pull both wires off the radiator fan thermo switch and touch the contacts with the ignition on, shouldn't the fan run? If so, that would be a good test of both the fuse and the fan motor.

Ruger said:

Jackrabbgit, the fan is roughly 4 inches in diameter.

OldNewbie, if you pull both wires off the radiator fan thermo switch and touch the contacts with the ignition on, shouldn't the fan run? If so, that would be a good test of both the fuse and the fan motor.

Click to expand...

Yup, that should do it. Maybe with ignition off, I don't know, my bike doesn't have ignition and the fan wire is always hot.

Side note - buy fuses and carry them with you. They're light, easy to change, and make things work a lot better.

My fan quit a couple weekends ago. I knew it had a fuse of its own when I installed it, but never bought spares....

There is a bit of good info in this post:
radiator fan fuse keeps blowing

SilvFx said:

I ended up picking up the Beck/Arnley 2011310 switch which is a 95C/91C switch. Cost was $13.65. Shipping to my zip code (Denver, Colorado) was $1.61. The Beck/Arnley 99C/95 switch (2011312) is $5.75 with $1.64 shipping.
There are several other brands that you may like better with varying temp specs (and some are hard to tell the exact specs unless it mentions in the description).

I can assure you the Beck/Arnley switch I purchased (2011310) is an exact fit/copy to the 2010 OEM switch with the exception of lower on/off temp.

Click to expand...

Digging up an old thread here I know, but I found this info useful. I installed the KTM fan kit on my 450 and the engine has to get quite a bit hotter than I'd prefer for the fan to come on. Ordered this part from ebay and should have it by Wednesday.

Hopefully this will remedy the issue. I should find out by next weekend.

How are you guys mounting the fan? Just using the pull through plastic cable/clip things?

bumping an old thread, but perhaps someone can help, and nice to keep all this info in one place!

I've noticed the fan (normal ktm fan kit) isn't coming on anymore on my 2011 390, did a test and confirmed that after idling for awhile it'll spew coolant all without the fan coming on.

So i've done some things i read in here:

Bridge the thermo switch connections - fan turns ON
Checked the fuse in the fan wiring - looks good
Checked the wiring connectors and they look good (just visual inspection)

If I bridge the thermo switch and the fan comes on, this proves the wiring is good, is that correct? Shows that it's getting power, etc... ?

Does this mean that the thermo switch is bad? I'm calling around to local places tomorrow checking if I can find one of the BMW type thermo switches mentioned.

Thanks!

jeff

Looks that way yes, change the thermo switch.

Have the Beck thermo switch on order - will report back when it's in, thx!

Back in 2013 I replaced the factory thermo switch, and I don't believe that the fan has come on since. The factory switch is a 100/98 degree unit, and I replaced it with NAPA PN 1435033 which is a 95/90 degree unit. The fan runs when I jumper across the thermo switch connections, so I know the fan is fine. Hate to replace the thermo switch without knowing whether there's anything wrong with it, and I know they're difficult to test. Has anyone ever installed a manual switch for the fan? If so, please share your experience with that setup.