Grip Heaters too Hot and Code 81

[Ruggybuggy]

So the sled is a 07 FX and when I bought the sled the grip heaters were terrible. I installed the updated harness from Yamaha and this seemed to help somewhat and were "adequate". When I stretched out my skid to 144 I also bought the handlebars from the mountain as well. After I installed the MX bars with the stock grips I now have the hottest grips I've ever had on a sled. If I set the to the half way point it's too hot. I normally ride around with the grips set at 1-2 bars showing. Today it's extremely cold here. Riding temps. were -23C and I still was able to wear light gloves and grips set at about a 3rd. I was off the sled for a bit and my hand got a bit cold so when I got back on I cranked them up to full. After about 10 min code 81 came up and the grips shut off. I turned the sled off then restarted and everythings fine if I don't crank the grips up. For some reason the ECM is thinking the grips are shorted and shutting them down.

 

[Boy21]

ground wire update? check yellow grounding block sticking out of the wire harness between the rad n oil tank. could be burnt

 

[Ruggybuggy]

ground wire update? check yellow grounding block sticking out of the wire harness between the rad n oil tank. could be burnt

Nope been done.

 

[yamahas]

Sounds like there is a problem with the wiring? You have all stock components just mixing fx and mtx?

Possibly a hot spot on the warmers causing a open/short?

 

[Ruggybuggy]

Sounds like there is a problem with the wiring? You have all stock components just mixing fx and mtx?

Possibly a hot spot on the warmers causing a open/short?

All the wiring is stock with the Yamaha update. Just the MX bars with grips on the FX. The only time I have an issue with throwing the code is when I turn up the grips to full. Even at half they are still too hot. I usually keep them on 1 or 2 and that's with light gloves on at -25C. Just find it strange how everyone mentions their grips don't have enough heat and I have the opposite issue.

 

[Mooseman]

I experimented with that update harness. It basically changes the grip wiring configuration from series to parallel. They would burn my hands if I left them on full. I took it out. My son's '07 FX had it when we bought it. The grips get hot just on one bar. If he goes to four or five, he gets that code. Because the power draw is essentially doubled, the ECU thinks they're shorted. The grips weren't designed to run in this configuration. The harness was for one particular year and model with hooked bars ('08 GTX and MTX).

Although the ECU will protect itself from the increased power draw and shut down the hand warmers if too high, it could overtax the stator if it doesn't.

Although mine are adequate, they take a while to get warm because they are controlled by the ECU by PWM and varies by RPM. If you want to see how PWM works, here's a video that shows a Nytro's handwarmers working on an oscilloscope so you'll understand why they get cold again when you stop (same as on all Yamahas). If you were to connect a light bulb instead of the warmers, it would get dim at idle and get brighter as you speed up. Even at full throttle, they never get 12V for 100% of the time.

I'm thinking of bypassing the ECU control altogether and just rewire them in series with a switch and resistor, just like the old days. I think if they're left off on the handlebar, the ECU won't complain.

 

[Ruggybuggy]

Thanks for that explanation. Explains everything. I guess I'll take out the update when it gets warmer.

 

[cannondale27]

I experimented with that update harness. It basically changes the grip wiring configuration from series to parallel. They would burn my hands if I left them on full. I took it out. My son's '07 FX had it when we bought it. The grips get hot just on one bar. If he goes to four or five, he gets that code. Because the power draw is essentially doubled, the ECU thinks they're shorted. The grips weren't designed to run in this configuration. The harness was for one particular year and model with hooked bars ('08 GTX and MTX).

Although the ECU will protect itself from the increased power draw and shut down the hand warmers if too high, it could overtax the stator if it doesn't.

Although mine are adequate, they take a while to get warm because they are controlled by the ECU by PWM and varies by RPM. If you want to see how PWM works, here's a video that shows a Nytro's handwarmers working on an oscilloscope so you'll understand why they get cold again when you stop (same as on all Yamahas). If you were to connect a light bulb instead of the warmers, it would get dim at idle and get brighter as you speed up. Even at full throttle, they never get 12V for 100% of the time.

I'm thinking of bypassing the ECU control altogether and just rewire them in series with a switch and resistor, just like the old days. I think if they're left off on the handlebar, the ECU won't complain.

Mooseman wont a code be thrown just from disconnecting the stockers? You would have to fool the ECU into thinking they were still on there. Or just get Yamaheaters.

 

[Mooseman]

Maybe not if you don't turn them on. I might have to put a resistor in the circuit to fool it. I just find Yamaheaters too expensive, especially now with the value of our Canadian peso. Just a summer project I'm thinking about.

 

[MikeWalters]

I just find Yamaheaters too expensive, especially now with the value of our Canadian peso.

LOL, I couldn't have said it better myself! Hahaha! And yes, I read up on Yamaheaters and scratched my head...lot of money... works fine no doubt but Ive never had a problem with yamaha heaters (but, Ive never owned a nytro lol)

I have the update, and my warmers are perfect. When Its cold I put them on max, they get hot but not too hot. I did not do the update myself so no idea what was done, or if done correctly. The guy I bought the thing from never did ANY of the updates, aside from handwarmer harness and rad fan. I should check mine over too