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Duke

Who has aftermarket heated grips controlled by OEM menus

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Posted (edited)

I just finished installing mine today. I haven’t had a chance to use them on the road yet, but they heat nicely in the garage.

I just couldn’t see spending so much on factory grips that seem to have quality and reliability problems.

If a how-to post would be helpful, I can do one. If it’s already been done, I won’t bother. 

Edited by Duke
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Old enough to know better, but young enough to do it anyway.

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I didn’t take any pictures of the actual grip heater element installation, but there’s nothing special about that. The important part is getting the wires connected correctly so the ECU senses resistance, which enables the grip options in the menus.

I tried several different combinations of connections, and spent quite a bit of time trying to understand how the ECU was controlling the current flow through the grips, before coming up with a workable combination.

I’ll draw up a wiring diagram and take a few pictures of the actual connections I made on my bike, but it’ll be a few days before I can get it done.


Old enough to know better, but young enough to do it anyway.

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Please elaborate more about the exact model and prices.

Thanks

 

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the ECU senses the resistance of the heated grips when they are in "series wired in", _parallel_ does not work, thats all iirc.

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1 hour ago, Tracerracer said:

the ECU senses the resistance of the heated grips when they are in "series wired in", _parallel_ does not work, thats all iirc.

The computer doesn’t actually care if the grips are in series or parallel. All it sees is total resistance. 

If it senses too little resistance (short) or too much resistance (open), the menu option will not appear. I don’t know exactly how much resistance it expects, but I do know two values that allowed the menu option to appear. 


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Posted (edited)

Ok, I'm not going to bore you with pictures, and instead I'm just going to explain why I have things connected the way they are, describe how I have everything connected, and provide you with a crude wiring diagram so you can follow along.

First, the disclaimer. I am not advocating that anyone do this with their bike. I am only describing what I've done with my bike. I have no understanding of anyone else’s abilities, so proceed at your own risk.

I am hoping that others will join in the discussion to further everyone's understanding of Yamaha's OEM grip heater technology. Actually, calling it technology is a gross overstatement. The only thing technical is the fact that the pulse width modulation (PWM) is being provided by some kind of microcontroller (presumably the ECU) which is controlled by the menus on the dash. Other than that, the rest of this just requires a basic understanding of Ohm's Law and how PWM can adjust the heat output of the heating elements.

All this having been said, please do not dump all over this thread. Instead, please ask constructive questions and provide constructive feedback. I am NOT an expert in all things Yamaha or in all things technical/electrical/electronic; however, I do have a professional background in electronics from which I drew my conclusions. With each of us bringing our own knowledge, experience, and general common sense to the forum, let's make the best use of all three and see if we can collectively come up with a properly working, safe solution that any of us can use.

Now for the meat of this post.

As you saw in an earlier post, I used the Heat Demon brand of grip heating elements. I’ve found their product to have reasonable quality control and reliability. The only thing you will use from the kit are the elements themselves and the heat shrink for the left grip. Everything else is not needed since you will control the heat output from the OEM menus.

I won’t bore you with how to install the heating elements. That has been covered in exhaustive detail in countless places on the Internet. Just know that you need to route the wires for both elements to the right side of the bike where the two factory heated grip connectors are located. It is up to you if you want to cut off the factory connectors and wire direct, or if you want to buy some of the correct connectors (the same ones as used for our blinker connections) to connect to the heating elements and then plug into the factory connectors. This is what I did, and it works great.

Once you have the grips installed and the wires routed, your next step is to make the correct connections. This is where this thread could go entirely off the rails, so please read carefully and bear with me.

If you look at the wiring diagram for the bike, you will find that the factory heated grips are connected in series. This fact created a challenge for me due to the large quantity of conflicting information on the Internet regarding the resistance of the factory grips. I’ve found information stating everything from 1.5 to 2.5 Ohms per grip with some degree of accuracy, so I chose to use 1.5 Ohms for my purposes. This means that the factory configuration results in the computer seeing a total resistance of 3 Ohms.

Another challenge is that the Heat Demon grips are designed to be used with a rocker switch to control the heat output, and that switch only provides off, low, and high as options. Because of this the heating elements have three wires, which can cause additional confusion. How do you connect grips with three wires into what is a two-wire system on the bike?

The answer to this question comes from Ohm’s Law. The heating elements are nothing but resistors. The three wires exist only because the elements actually consist of two separate resistors to accommodate the low and high settings. You can choose to connect the wires in a variety of configurations, but by using one wire as the input and combining two wires on the output, you wind up with the two resistors in one grip connected in parallel, which results in a resistance of 4.8 Ohms per grip. If you only connect one wire on the input and one wire on the output, the resistance is higher (thanks to Ohm’s Law), and this configuration will not work for our purposes. In fact, 4.8 Ohms is a compromise, but so far it seems to be a workable compromise for me. Only time and further testing will prove if this compromise functions as needed.

Now, if we connect the two grips in series the way the factory grips are connected, we will wind up with 9.6 Ohms of total resistance. This is more than three times the total resistance of the factory grips connected in series, which results in less than one third of the heat of the factory grips. This is the first configuration I tried because I was simply following in the footsteps of Yamaha. Even though the ECU recognized the elements as heated grips and provided me full access to all the associated menu options, this configuration was a failure. I could barely feel that the grips were heating when running at full blast on a 70-degree day. Back to the drawing board.

Next, I started thinking about ways that I could increase the heat output of the heating elements. According to Ohm’s Law, this means that I must change one of three variables, which are voltage, current, or resistance. I had already cranked the settings in the menu to their max, so there was nothing more I could do to increase voltage. With voltage fixed, the only way to increase current is to reduce resistance. But how do you reduce the resistance of a fixed resistor?

Back to Ohm’s Law. I had two identical resistors in the form of two 4.8 Ohm heating elements. What if I connected them in parallel instead of in series? The resulting total resistance would be 2.4 Ohms, which is 20% less resistance than the factory grips when connected in series. Would the ECU accept this resistance and allow me to access the heated grip menus? Would this result in my ECU going super nova and destroying the earth as we know it? The simple answers are YES and NO!

By connecting the two elements within each grip heating element in parallel, and them connecting the two grip heating elements in parallel with each other as well, I arrived at a resistance that was low enough to allow the ECU to offer the heated grip options and to actually drive the heated grips at an acceptable level.

FYI...with the grips connected in parallel, you do not have to worry that your bike will go up in flames should one grip fail. What will happen is that total resistance of the circuit will double due to the loss of the parallel leg, which will result in the total current flow actually decreasing instead of increasing. Basically, one grip will be cold and the other will be lukewarm at best. The good news is that this should actually make troubleshooting which grip has failed just a little easier.

Early on in this post I mentioned PWM, but I haven’t mentioned it at all during the post. Well, that’s because it’s not directly relevant to the problem at hand, but it is an interesting subject that you might do well to research to understand how the bike controls the heat of the grips.

I’ve also mentioned Ohm’s Law several times in the post. I won’t even try to explain the concept, because like so many thing other things you can find it well explained on the Internet, including explanations of series and parallel resistance.

Thanks for reading, and please feel free to offer perspectives and feedback or to ask questions. If I don’t have an answer, I suspect someone else will offer one up.

I'll try to attach my wiring diagram to the next post.

Duke

 

Edited by Duke
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So, here is my very simple wiring diagram for the final product. The wire colors are representative of the grip heating elements (red, white, and blue), the positive from the bike (Yellow/Blue), and the ground from the bike (black). As you can see, you connect the white wires from both heating elements to the yellow/blue wire from the bike, and then you connect the red and blue wires from both heating elements to the ground from the bike.

Diagram.png

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I've got Oxford heated grips. I'm not sure how they are wired or controlled but they do work very well. I'd love to be able to control them from the bike.

I think it's worth it to do some investigating...

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On 4/20/2019 at 6:10 PM, Duke said:

I just couldn’t see spending so much on factory grips that seem to have quality and reliability problems.

 

What were these "quality and reliability problems" with the factory heated grips? 


***2015 Candy Red FJ-09***

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Posted (edited)
10 minutes ago, betoney said:

What were these "quality and reliability problems" with the factory heated grips? 

I read several posts where the grips had failed after too short of a time period after install. I also feel that the design is overly complex, and I like the stick on elements because I am free to run whatever grips I want. 

Edited by Duke
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Posted (edited)
16 minutes ago, nicksta43 said:

I've got Oxford heated grips. I'm not sure how they are wired or controlled but they do work very well. I'd love to be able to control them from the bike.

I think it's worth it to do some investigating...

Start by measuring their resistance. That will help you determine if they are capable of being integrated. 

Also, if you do some research on advrider in the Super Tenere BIG thread, I believe people have integrated the Oxfords. I have to believe that the ECU and factory grips for both bikes are very similar. 

Edited by Duke
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