Low Temperature Switches - Examined

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VMAX Eddie

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Topic:
I have read more than a few posts now about the temperature problems with the VMAX. It was one of the first things that brought me to this forum after purchasing my Mr. Max this year, seeing it for myself, then searching for a solution.

On this forum there is a split for those who use manual switches and those implementing lower temperature fan switch sensors. This post is for those using the lower than stock temperature switches and examining the options available.

Myself:
I personally have purchased the Vmax Outlaw low temperature switch http://vmaxoutlaw.com/merchandise/index.htm and am in the process of deciding to use it. I have had some issues with it already. The primary one at this point is that it comes on WAY too soon. I metered it from a cold engine while running and the switch closed at the small triangle just above the C on the temperature gage.

I further tested it by immediately removing the radiator cap and sticking an oven meat thermometer into the radiator fluid. I got a reading of 150F. There could obviously be some discrepancy there so lets say (+ or - 10F) is reasonable. Either way around 150F is far to soon for it to be coming on and will make the fan continually run which will kill the battery and put an unnecessary toll on the electrical system.

Switches:
I found this link:
http://users.telenet.be/pianne/technical/A-Z.htm

Which lists three suggested lower temperature switches for our high temp problems on the VMAX:
Replacements are : BORG-WARNER TFS-545, WELLS-SW537 or NAPA FS-147switch.

I have read on vmaxforum.net that some people use the VMO, the Borg, or the NAPA, the third I have not read about. One of the key issues I am running into is WHERE ARE THE SPECS for these switches?? And how can we make a determination of what is best without this information?

Background (Stock Switch):
To start with we need to look at the stock switch. Here is the info I find from the Yamaha Vmax Service Manual:
The electric fan will not turn at coolant temperatures of 105 3°C (221.0 37.4" or more:

The electric fan is controled by the therm ostatic switch when the main switch is “ON”.Thus, undercertain operating conditions,this fan m ay continue to run untilthe engine temperature
has cooled down to about91°C (195.8”

AND

temp-switch-test_zpsa51a7fa9.jpg


From these specs what I see says stock switch turns on around 221F and back off at around 208F.


The other switches--------

NAPA FS-147:
If you visit the NAPA website and view the switch here is what you see:
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Coolant-Fan-Switch/_/R-ECHFS147_0365986580

The specs listed on the site say:
Coolant Fan Switch Temp Rating : On At 194-203 Deg. F.

Sounds perfect right? But wait there is a major discrepency! When I called NAPA and then visited the local store to check this info and availability the service employee saw the same thing I did. So he offered to call the manufacturer to verify and I said SURE. What came back was that it turns on at 225F, :bang head:

The service employee suggested his best guess would be that it turns back off at the 195-203F listed, but didn't know for sure. So by the manufacturer's own information this switch is basically identical to the stock switch in terms of ON temp.



BORG WARNER:
There is no contact phone number on their website and I did not bother to fill out the form which may never get answered or many days from now. I did find this:
Jason, buy the time your fan comes on your at 230*. Get the Borg warner
thermal fan switch #545 and it will come on at 205*.
on here:
http://www.the-clearing.org/Bike/Vmax/Tech/cooling
But that is speculation as far as I can tell. So as for the BORG-WARNER there are no specs that I can find.
Besides that I cannot find where to buy one anyway.



WELLS:
This brings us to the Wells. I was not able to find a spec sheet but I was able to call their their tech team. He quoted as saying:
Normally open switch which closes between 193-205F
And I do find these listed on Ebay, etc.

Conclusion:
I would like to hear about any personal results you all have found with these. Which one works, which one doesn't, and why.
I know many are using the VMO switch, but my findings are not good. Again it simply turns on WAY too soon. I could simply have a bad switch. What are those of you who use the VMO switch seeing for on/off temps? What spot on the temp gage?

Same question for those using one of the other 3, and feel free to input any other helpful info regarding automatic fan switch solutions.

Thanks guys, I hope we can clear up the myths about these automatic switches and really nail down what the best switch is for those of us who want an automatic solution for our MAX!
 
I tried to find anything from where I bought mine can't find it of course. Box that came with it has orange vmax letters and smaller black letters vm - ts on it . I have an 85' and the needle used to touch the red now with new it stay's at mid point . I may try thermometer and see where its at . I was told thru website keeps it around 200 degrees
 
What is the thread size of the fan switch/sensor ?

I work for a large sensor producing company, most everything we make is some sort of temperature control.

We have one product that would work perfectly, if I could get a thread match. That part is not looking good. It appears very close to a 3/8-18 American thread. Only thing we have that will fit in is a 3/8-18 NPT. The Venture stock sensor I have is a straight thread.

If I can get time to check and see if I can get the NPT to seal in a straight thread bore, I can put a o-ring seal on it like stock has.

Now is the nice part, maybe. Since we make these and I am the R&D mechanical design engineer, I can possibly get a temp disc custom 'bumped', to work at a more optimal range.

At some point, probably would not get it done this summer though. Just something for me to think about.

http://new-power.biz/files/48T.pdf

http://datasheets.globalspec.com/ds/106/thermodisc/AC2A0BC1-3E45-486D-A096-8008DFF9DA6F

Gary
 
What is the thread size of the fan switch/sensor ?

Wow thanks Gary! If you could put something together that works well on the VMAX I think you would sell a lot of them.

I can't find anything in the Service Manual about this but if the listing for the NAPA FS-147 is correct, and I would assume it is since people are using it, it shows:
Coolant Fan Switch Thread Size*:*M16 x 1.5"

If someone who is a full blown mechanic can verify the thread count that would be great.

I would love to know the actual temps in relation to the stock temperature gage. Maybe someone out there with one of those fancy temperature guns they use in HVAC work could do some research for us.
 
I had heard venture guys were putting in vmax sensors because they turned on sooner, dont know but if there were the thread woulds be the same size I would quess.
 
I have been running the Outlaw switch for about 2 years now. Zero problems. It turns on as you say, mid way, and I have never had a problem with it. The max does like hot so a manual switch actually makes more sense. What can I say. I'm lazy and I kike it...but as above.
 
I'm using a Beck Arnley 201-1373, apparently it is meant to open at 194 and close at 185
41WMTMJF7EL._SL500_AA300_.jpg


But, since I put in my digital speedo with a temperature reading I noticed it wouldn't come on below 215...
so I took it out and tested it in a pan of boiling water, nothing!
put a gas torch to it and it switched on - I now have an override switch and I'm on the look out for a proper thermoswitch
 
An interesting thread, for sure. Plenty of concerned folks, and some great research and information made available. However.............
There may a "smoking gun" explanation, that hasn't been addressed here, or on a multitude of other temp-related discussions.
What if the temperature range of a stock operating engine is completely normal, and as designed???
- The gen 1's were produced from '85-'07. Did Yamaha Motor Corp. change (lower) the operating temps during that time span? This would have been a very inexpensive re-design, as many people have demonstrated, by just changing out the sensor. Since owners of all model years have concerns about overheating, it would seem not. I guess just a check of part number changes, if any, would confirm that the original '85 design has not been altered. Additionally, Thermostat, thermoswitch, and temperature sensor information is available in the Clymer manual. No difference given for model years.
- Again, could it be that the normal operating range of the coolant was determined to be the best for this particular engine?
- Could it be that many** owners have fallen into a type of mass panic hysteria, caused by that pesky analog OEM temperature gauge, with the ambiguous "red zone" warning? For those that have installed gauges with numbered faceplates, or digital gauges, what is the actual operating range of your bikes?
- Just playing Devil's advocate, or just giving food for thought. Your call!

** - I'm one of those. I put in an overide switch years ago. I have used it occasionally, in hot weather, and extended idling conditions, when the needle has hit that dreaded :damn angry:red zone.
Cheers!
 
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My 94 ran like crap when it got really hot, I did the 180 thermostat swap and put in the Borg & Warner lower temp fan switch (can't remember the part # but if you search the motor tech section its there) and it runs much better and the fan doesn't run all the time like others say and if it does I suspect they have other issues. I have a Vapor speedometer with a digital temp readout and my fan comes on at 205-208 and shuts off at 198 and its about perfect I think. Still been tossing around the idea about a manual switch for faster cooling at the track but I already have too many damn switches (air compressor, nitrous arm, and had to put one on for the headlight because my starter button is nitrous activation and the headlight would go out on spray, and have another bar mounted switch for my bottle heater) so I'm basically out of room and the auto switch does work well. Just thought I'd add my experiences to the thread.

Sent from my ADR6425LVW using Tapatalk 2
 
I have a VMO switch. Works flawlessly. Cuts on at halfway on the temp gauge. Had it for several years now. Maybe yamaha had a reason for letting it run as hot as it did, but they didn't have sense enough to make the gauge read normal. Red causes panic.
 
I've bought a manual switch (not fitted, yet). Nor because of the gauge reading high, but because of the amount of heat I was feeling on my legs when in traffic (on a hot day). My gauge isn't working, so I don't know the actual temp, and the switch is a cheap, neat, quick fix for the time being.

Sent from my Nexus 7 using Tapatalk HD
 
I've bought a manual switch (not fitted, yet). Nor because of the gauge reading high, but because of the amount of heat I was feeling on my legs when in traffic (on a hot day). My gauge isn't working, so I don't know the actual temp, and the switch is a cheap, neat, quick fix for the time being.

Sent from my Nexus 7 using Tapatalk HD


Only problem, when you turn the switch on you will get much more heat on your legs! I have the switch but really never use it. I live in Texas which gets VERY hot. Only time my temp gets even close to the red zone and the fan automatically turns on is in stop and go traffic on those 100 degree + days. If your system is clean and coolant is in good shape I don't think there is a problem.

The running poorly when very hot is often caused by the charging system not putting out enough juice for the ignition system to function properly.

So I guess I support the "mass hysteria" theory.. :biglaugh:
 
+1 M-cman!
No overheating issue with mine, gauge always under the middle dot, unless stuck in heavy summer traffic for a while, so gauge is above the dot but never touch redzone.

But many French Vmax buddies have the same overheating problem, they always ask me why my temp is so low.....

1) My gauge and sensor are not working properly

2) My custom coolant mix make the difference .
I use good brand ones but with the less amount of glycol available ( the less glycol and the more water in the mix, the more efficient it is) and i mix it with tapered water and Waterwetter. Air temp never goes down under -15°C where i live so i don't need strong antifreeze properties...
 

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