FCS Thermal Creep Switch Issues
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Banned
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From: WV
FCS Thermal Creep Switch Issues
Ok, Im laying it out there clean for everyone to digest and make an informed decision that best suits their needs. Most importantly the vast majority of users are not having issues, but the small number of reported problems is still more than I am willing to accept, I want the best performance possible for my customers so I am seeking a better solution. Please keep inmind that I am not an electronics engineer, an issue of this nature would be challenging even for an engineer, but I will get this resolved. Im actively working with the manufacturer for a solution, the lab analysis results for all 17 switches I sent in exhibit the same material erosion/transfer condition on the contacts, resulting in contact bridging and gradual lowering of the switch calibration temperature. The technicians are reporting this is typically associated with 1/2 or square wave rectifiedDC power. For our full wave charging system application that simply suggests that this thermal switch issue is a result of a faulty charging system. There are a couple reasons this gets a little challenging; a replacement switch resolved the problem for a couple folks, but others had repeat failures of thesame nature. How can this be possible; all OEM components my be more tolerant to charging system irregularities. I got a lot of great input from one particular HDF member who experienced two consecutive failures in short order. When I emailed him about the charging system possibility he asked me to give him a call. His aftermarket tuner was showing diagnostic trouble codes for the charging system so he took it to the dealership and their diagnostic scan passed. He replaced the voltage regulator anyway and installed another new thermal switch, so far no more switch failure. Its a bit early to draw any conclusions from this one case, but it is an encouraging observation. Im not going to claim that everyone with switch problems has the same issue, but it is going to be damn near impossible for me to convince anyone they might have a charging system issue when the dealer scan comes back clean. There are several possible solutions Im looking into, but what Im really shooting foris the simple and effective solution. Im looking at trying some different contact materials, and some snap action switches to possibly try with anyone who reports a failure. This will be functionally different from the creep switch; the creep is slow acting so it tends to flutter back and forth between open and closed when it is right at the calibration temperature, likely occurring during post operation cool down as the engine heat sinks and the fans cycle on and off. Its an assumption on my part that the switch action type might be an issue but its worth evaluating in operation. The snap action is fast acting and will have a much wider differential open/close temperature. I want to maintain the 90C calibration for the off temperature so the ontemperature will be higher, but I cant quote a value just yet. So in a nutshell, some unforeseen issues have developed with this relatively new product that need resolved. The quality of the switch itself is not the issue, but rather the individual charging systems may possibly be the problem. Thanks for your patience while I find a viable solution. I'm not denying there is an issue to be dealt with but it is not an epidemic, over 95% of users have not reported any issues. Anyone who has an issue but has not addressed it yet, please contact me directly via email jason@wardspartswerks.com , it will be far more productive than trying to engage it on the forum. I wont leave anyone hanging. More to follow as it develops, I do appreciate your patience.
Thanks
Jason
Thanks
Jason
Grand HDF Member
Joined: Jan 2010
Posts: 3,515
Likes: 1,994
From: Vancouver BC
Instead of using a switch with contacts, why not use a thermistor that drives a FET to activate your fans? You could even add a simple timer to give a bit of hysteresis to keep the fans from fluttering on and off when hovering around your set-point temperatures.
Just a thought.
Just a thought.
Thread Starter
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Banned
Joined: Apr 2012
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From: WV
Instead of using a switch with contacts, why not use a thermistor that drives a FET to activate your fans? You could even add a simple timer to give a bit of hysteresis to keep the fans from fluttering on and off when hovering around your set-point temperatures.
Just a thought.
Just a thought.
Grand HDF Member
Joined: Jan 2010
Posts: 3,515
Likes: 1,994
From: Vancouver BC
Try placing a diode in series with the switch to prevent any back EMF generated by the electric fans from spiking the switch. You could also place a 0.1 mfd capacitor across the switch to debounce it and absorb any high voltage pulses.
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Banned
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From: WV
Thermal switch info update
So the down and dirty is I don't have an answer for why some folks have experienced problems with the creep switch. Most users have no problems withit, some have tens of thousands of trouble free miles, and some have craped out within a few days. I thought I was onto something with the member who swapped out his voltage regulator, but his replacement switch has malfunctioned also. I can’t explain it because it is beyond my scope of understanding, and I’m not tryingto feed anyone BS about it. Up to this point I have responded with the info supplied to me by the MFR’s engineers based on their analysis of a good sampling of failed switches from customers. They suggest the erosion and transfer of contact material is evidence of a charging system issue, but it is lacking any in-depthexplanation of the condition, so I’m moving forward looking for a different switch that will not exhibit this problem.
I’m currently testing some new switches but their function is different. One customer already declined to try it because its functional characteristics are different from the original creep switch; he was accustomed to the fans coming on at 190F with the creep and didn’t want the fans switching on at 250F with the snap, he just felt it was too high. I would like some more feedback from users; I’m concerned there may be a potential psychological barrier since I have already established the “normal” operation with the creep switch, so anything new and different may seem “wrong”. The creep switch is a slow action device with a narrow on/off differential, it turns the fans on and off at about 190F, which really is a good calibration temp to maximize cooling potential. For the benefit of those not familiar with this subject, the creep switch does not maintain a head temp of 190F, that is simply where it comes on, then the fan system slows the climb to the stabilized temp, depending upon conditions. The snap action switches I am testing have a wide reset differential between on and off temperature, which raises some new considerations; the fans come on at about 250F,which is still acceptable in my opinion because that is just a little higher than the average where most bikes normalize with the fans running, under moderate operating conditions. With this new switch on my bike, the fans come on at 250F and then drop back down to about 235F, then depending on duration and intensity of the ride, the temp may hover at 235F or slowly creep back up to 250F. The fans go off at about 160F, which is lower than the creep switch, so the fans run a little longer during post operation cool down, but they don’tcycle on and off as the engine heat sinks. Because of the wider differential, I had to compromise with the on/off temperature, I could go with a lower calibration and have them turn on at say 190F, similar to the creep switch, but the off temp would be like 100F so the fans would run much longer, or even continuous in hot climates. I could go with a higher calibration so the off temp would be 190F, similar to the creep switch, but they wouldn’t come on until about 280F. The functional characteristics of the snap type switch may prevent ideal operation temperatures, but it should provide a much more durableand reliable automatic switch solution for this application.
Another observation was short trip operation, if I just ride a few miles or minutes, about 5 or less, the fans may not come on and the CHT can be almost 250F at shutdown, this probably won’t happen too often so I’m not sure it’s a major concern but, it warrants mention.
The positive attributes of this new switch are, sealed construction, housing is nonconductive so no more Mylar sheath to deal with like the creep switch, much higher amperage rating, it is also smaller at about ˝ the size of the current creep switch. The downside, the install is a little more involved and can’t be rushed, overnight cure for the RTV is absolutely necessary, no more “stuffit in there and go”. Also the snap switch has light colored wires; once installed it is hidden behind the fans and not really visible unless you arelooking for it, but they can be covered with a black sheath so not a big deal.Custom configuration with black wires/housing and/or a narrower reset differential requires a 10,000 pc order so that probably isn’t happening, I’ll go with a standard configuration.
Mounting a different type of switch is the major stumbling block, there are all kinds of thermal switches available, but mounting them to the cylinder head is another thing. Robust thread-in type surface mount switches are available, but they require a threaded hole in the head, which most people will not be able or willing to drill and tap their head to add a thermal switch. I want to stay with a simple thermo-mechanical contact type switch on the cylinder head for a couple reasons; simplicity and function, when you move the switch to the rocker cover, or any other lateral component, too much heat and transfer time is lost when the probe is not placed directly on the head; the result is inconsistent on/off temps.
As mentioned numerous times in the past, I will stay on it until I find a simple solution; I’m not going to add diodes, capacitors or any other components to create a sub-system and force this to work. If I can’t find a suitable trouble free switch for this simple application, I will default back to manual operation just like before I offered a thermal switch. Feedback is welcome; I’m trying to establish if folks will be receptive to the characteristics of this new switch. I did purchase a small batch to start sending out as a replacement for failed creep switches, they should be in by early Oct. They are calibratedabout 10F lower than the samples I got, so they should bring the “on” temperature down to about 240F and the “off” temp to about 150F, I believe this is about the best compromise within the functional limits of the switch. I think the automatic function alone is more important than the actual temperature values of the on and off functions. Removing the human error of forgetting to turn them on, or waiting too long to turn them on is what really helps to maximize the performance of the system. Regardless of what type or temperature calibration, with a thermal switch in the system, as soon as the engine warms up, the fans come on every time, no waiting to be reminded by the EITMS thump to turn them on.
Thanks all
Jason
I’m currently testing some new switches but their function is different. One customer already declined to try it because its functional characteristics are different from the original creep switch; he was accustomed to the fans coming on at 190F with the creep and didn’t want the fans switching on at 250F with the snap, he just felt it was too high. I would like some more feedback from users; I’m concerned there may be a potential psychological barrier since I have already established the “normal” operation with the creep switch, so anything new and different may seem “wrong”. The creep switch is a slow action device with a narrow on/off differential, it turns the fans on and off at about 190F, which really is a good calibration temp to maximize cooling potential. For the benefit of those not familiar with this subject, the creep switch does not maintain a head temp of 190F, that is simply where it comes on, then the fan system slows the climb to the stabilized temp, depending upon conditions. The snap action switches I am testing have a wide reset differential between on and off temperature, which raises some new considerations; the fans come on at about 250F,which is still acceptable in my opinion because that is just a little higher than the average where most bikes normalize with the fans running, under moderate operating conditions. With this new switch on my bike, the fans come on at 250F and then drop back down to about 235F, then depending on duration and intensity of the ride, the temp may hover at 235F or slowly creep back up to 250F. The fans go off at about 160F, which is lower than the creep switch, so the fans run a little longer during post operation cool down, but they don’tcycle on and off as the engine heat sinks. Because of the wider differential, I had to compromise with the on/off temperature, I could go with a lower calibration and have them turn on at say 190F, similar to the creep switch, but the off temp would be like 100F so the fans would run much longer, or even continuous in hot climates. I could go with a higher calibration so the off temp would be 190F, similar to the creep switch, but they wouldn’t come on until about 280F. The functional characteristics of the snap type switch may prevent ideal operation temperatures, but it should provide a much more durableand reliable automatic switch solution for this application.
Another observation was short trip operation, if I just ride a few miles or minutes, about 5 or less, the fans may not come on and the CHT can be almost 250F at shutdown, this probably won’t happen too often so I’m not sure it’s a major concern but, it warrants mention.
The positive attributes of this new switch are, sealed construction, housing is nonconductive so no more Mylar sheath to deal with like the creep switch, much higher amperage rating, it is also smaller at about ˝ the size of the current creep switch. The downside, the install is a little more involved and can’t be rushed, overnight cure for the RTV is absolutely necessary, no more “stuffit in there and go”. Also the snap switch has light colored wires; once installed it is hidden behind the fans and not really visible unless you arelooking for it, but they can be covered with a black sheath so not a big deal.Custom configuration with black wires/housing and/or a narrower reset differential requires a 10,000 pc order so that probably isn’t happening, I’ll go with a standard configuration.
Mounting a different type of switch is the major stumbling block, there are all kinds of thermal switches available, but mounting them to the cylinder head is another thing. Robust thread-in type surface mount switches are available, but they require a threaded hole in the head, which most people will not be able or willing to drill and tap their head to add a thermal switch. I want to stay with a simple thermo-mechanical contact type switch on the cylinder head for a couple reasons; simplicity and function, when you move the switch to the rocker cover, or any other lateral component, too much heat and transfer time is lost when the probe is not placed directly on the head; the result is inconsistent on/off temps.
As mentioned numerous times in the past, I will stay on it until I find a simple solution; I’m not going to add diodes, capacitors or any other components to create a sub-system and force this to work. If I can’t find a suitable trouble free switch for this simple application, I will default back to manual operation just like before I offered a thermal switch. Feedback is welcome; I’m trying to establish if folks will be receptive to the characteristics of this new switch. I did purchase a small batch to start sending out as a replacement for failed creep switches, they should be in by early Oct. They are calibratedabout 10F lower than the samples I got, so they should bring the “on” temperature down to about 240F and the “off” temp to about 150F, I believe this is about the best compromise within the functional limits of the switch. I think the automatic function alone is more important than the actual temperature values of the on and off functions. Removing the human error of forgetting to turn them on, or waiting too long to turn them on is what really helps to maximize the performance of the system. Regardless of what type or temperature calibration, with a thermal switch in the system, as soon as the engine warms up, the fans come on every time, no waiting to be reminded by the EITMS thump to turn them on.
Thanks all
Jason
Last edited by WARDSPARTSWERKS; Sep 25, 2013 at 02:47 PM. Reason: formatting conflict wordsjoined
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Seasoned HDF Member
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Posts: 14,156
Likes: 11,247
From: San Diego, CA
Im trying to establish if folks will be receptive to the characteristics of this new switch. I did purchase a small batch to start sending out as a replacementfor failed creep switches, they should be in by early Oct. They are calibratedabout 10F lower than the samples I got, so they should bring the ontemperature down to about 240F and the off temp to about 150F, I believe thisis about the best compromise within the functional limits of the switch.
Thanks all
Jason
Thanks all
Jason
I am having no problems with my original switch. Great product Jason... thanks!
I originally wasn't sold on the auto switch feature and was going to just buy the fans and use the on-off switch. I decided to give the thermal switch a try. I must admit that I really like the auto feature now that I've used it...
But to answer your question, I would not hesitate to purchase these fans with the new switch as you described above....
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Novice
Joined: Nov 2011
Posts: 17
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From: Colorado Springs
Jason,
I was one that had a thermal switch go out, but in my case it took a few months. I've had a replacement in since July and had no issue with the replacement switch (though i do notice it seems to come on quicker than the old one, but i might have got it wedge into the fins a little deeper). And i would have no problem with the new type of switch. In fact, i would even prefer it, i have a short ride (5miles) to work every morning and in the winter i will ride when it's as cold as 25 degrees. The short ride doesn't allow my oil temp to get very warm and i would prefer it did to burn off any moisture that it might accumulate, so most of the winter i manually turn off the fans in the morning and flip them back on for the ride home.
I was one that had a thermal switch go out, but in my case it took a few months. I've had a replacement in since July and had no issue with the replacement switch (though i do notice it seems to come on quicker than the old one, but i might have got it wedge into the fins a little deeper). And i would have no problem with the new type of switch. In fact, i would even prefer it, i have a short ride (5miles) to work every morning and in the winter i will ride when it's as cold as 25 degrees. The short ride doesn't allow my oil temp to get very warm and i would prefer it did to burn off any moisture that it might accumulate, so most of the winter i manually turn off the fans in the morning and flip them back on for the ride home.
Road Warrior
Joined: Jun 2010
Posts: 1,717
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I believe this has been addressed already in Jason's thorough post if you bothered to read it.