protecting the ECU?

[IQTurboHound]

Lost my VR and ECu off 09 800 this weekend in a bad spot. Swithed the VR and ECU from a buddys 09 800 and it instantly smoked his too.

Had to then pull two sleds straight up a hill by hand in 2ft of fresh

Wondering why it smoked the second one. Thinking bad stator maybe.


Any ideas?

 

[440dart]

when i thought i was haveing wireing/ecu/vr problems turned out to be my fuel controler


when the sled was cold or i let it cool for some time it would take 10min before my check engine light, but i was checking to see if my ecu and vr were getting hot and they were just warm to touch maybe i didnt have enough ride time on it but i dont think they should be getting hot like alot of your guys sleds are doing


did i not ride it long enough from the time i left my shop to where i test probley total of 20mins and i always let my sled get up to 100deg before i take off or even move it

 

[diamonddave]

Lost my VR and ECu off 09 800 this weekend in a bad spot. Swithed the VR and ECU from a buddys 09 800 and it instantly smoked his too.

Had to then pull two sleds straight up a hill by hand in 2ft of fresh

Wondering why it smoked the second one. Thinking bad stator maybe.


Any ideas?

This is very interesting and what I was afraid may happen. This makes me think while possible the stator is bad, also opens up the possibility of a ground problem.

 

[ruffryder]

what are everyones thoughts on the stator issue? The stator is an output only device and is passive. I am not sure how the regulator or ecm going out would cause the stator to go bad. I would think it would be the other way.

Though, if you dropped a leg of the stator, you would have only two phases out of the three. With the regulator rectifier being a three phase system, the only effect that I think the loss of a leg would be, would be an overall lower averaged voltage, and less work for the regulator to do.

This assumes the the regulators job is to only CHOP the voltage, meaning it has no effect on a voltage lower then it was designed for.

Though, dropping a leg of the stator might cause some interesting things to happen on the regulator / rectifier.

On another thought, I wonder what would happen if the regulator failed in such a way as to short the terminals of one side of the stator. I wouldn't think this would have too much of an impact the stator, as it is just coils, but it might be possible that prolonged exposure to high currents (if high side is put to ground via regulator / rectifier fault) might take a side of the stator out.

Just trying to think through some causality in this deal. Interesting for sure!!

 

[crashnbash]

I was just wondering what the cfms of the fans being used was, and if you could put a fan in with to high of cfm and cause the vr to be to cold?

 

[Flatbed]

I have an 07 D7 with 1100 miles on it. We were boondocking through tight trees for about 3 hours with beer breaks off and on. Everytime I restarted and took off I had a lean stumble; It would come out of it at half throttle with some feathering. I did notice a burn smell once but I thought It was another sled by me.{ He was breaking in a new M8 } I have an idea after reading this thread, it was me. When we got back to the trail my sled would not tach over 7400. I'm thinking I smoked something and the heat theory with the slow boondocking caused the problem. I noticed my handwarmers took along time to heat back up for the ride back to the truck. I'm wondering if the warmers might have helped cause this also. Everything seemed to be working okay but the low RPM's and the brief burn smell has me worried. Can you test the warmers if they went to ground slightly? Or should I order me a VR?

 

[diamonddave]

I have an 07 D7 with 1100 miles on it. We were boondocking through tight trees for about 3 hours with beer breaks off and on. Everytime I restarted and took off I had a lean stumble; It would come out of it at half throttle with some feathering. I did notice a burn smell once but I thought It was another sled by me.{ He was breaking in a new M8 } I have an idea after reading this thread, it was me. When we got back to the trail my sled would not tach over 7400. I'm thinking I smoked something and the heat theory with the slow boondocking caused the problem. I noticed my handwarmers took along time to heat back up for the ride back to the truck. I'm wondering if the warmers might have helped cause this also. Everything seemed to be working okay but the low RPM's and the brief burn smell has me worried. Can you test the warmers if they went to ground slightly? Or should I order me a VR?

You'll need to perform some electrical testing on the sled before you start throwing parts at it. There is a service manual here on snowest that you can download for reference. There are too many causes to just automatically say that your VR is bad.

 

[Clarke673]

Has anyone mounted the ECU in a different spot?...Like lets say to the air box? This would eliminate the heat issue?

Just a thought. I have lots of them....and most are stupid.

 

[lognomore]

The ground for the engine is a wire that is in the harness going to the stator. When you pull the flywheel you will see a wire that is connected to one of the bolts holding the stator to the engine. I felt that with the wire being the only ground source to the frame that a ground strap was needed to reinforce the ground between the engine and frame along with grounding the plate that all the components were mounted to. Leftfield, I like the setup that you did with your fan. I have two rides on my sled since putting on the fan and it seems to be working really well, and keeps the VR cool. I_own_u, just remember all ideas are welcomed. It's what helps us keep things going.

 

[429dhm]

If short circuits are causing the VR failures, it might be due to all the factory unused connectors (the ones not plugged into anything) are not totally insulated or tapped off and the connectors exposed pins could be shorting to the chassis. The accessory DC connector near the top of the steering hoop and there are a couple of connectors at the front of the sled that could be touching the front pipe heat shield. Also could the ethanol plug be going to ground as well if left unplugged? I decided to tape off the connectors that are not used as a safe guard.

 

[diamonddave]

If short circuits are causing the VR failures, it might be due to all the factory unused connectors (the ones not plugged into anything) are not totally insulated or tapped off and the connectors exposed pins could be shorting to the chassis. The accessory DC connector near the top of the steering hoop and there are a couple of connectors at the front of the sled that could be touching the front pipe heat shield. Also could the ethanol plug be going to ground as well if left unplugged? I decided to tape off the connectors that are not used as a safe guard.

This is a good idea. Some of mine (not all) were taped at the factory.

 

[rocket]

Shorting connectors

Those connectors can and do short out to the aluminum plate covering the nose of the sled. I was doing some spring service stuff on my sled and moved the harness out of the way to complete what I was doing - when I put everything back in place, the sled wouldn't start. I fought with it and finally got it to start and when I started to close the hood, it quit again. I started checking wires at that point and realized one of those connectors was touching the aluminum plate. After I found that, I taped up all the open connectors and also taped the plate in the same area. I don't know if that would cause the VR problems, but it certainly isn't good for the electrical system. As far as the rest of the thread in general - some sort of zener circuit may be an answer, but it will need to handle a lot of current in order not to be fried itself. When the voltage regulator fails, it wouldn't surprise me if you had 25-30V in the system at high RPM. On older sleds, I've unplugged voltage regulators for testing and the system is approaching 20V before you even hit 5000RPM. The ECM will probably handle 16-18V at most, any more than that and it's likely toast. I'll maybe dig around a bit as well and see if there is anything out there for a voltage regulating IC that could carry a significant amount of current. Maybe there would be a way to have a regulating circuit that could also fire an "idiot light" to warn the rider of a problem - even shut the sled down if one wanted to get creative.

 

[theshadowrider]

Great info, what should I do.

This is all great info. I have read the tread completely and I am now wondering what I should do. Sounds like the consensus is a ground issue and cooling issue. Should I ground my sled out better? How do you? Could someone post some pictures on how to? What about the fan? Maybe someone who has done the fan could make a kit. I think that for me to do make a fan mod maybe over my head, but if someone sold a kit I would buy it?

Just a thought, seems odd that some sleds go 70 miles and some go 2000 before the vr goes out. I guess that is what makes this problem hard to figure out. Does anyone know what polaris says about this. Why is it so random on when they go out.

I wonder if the turbo guys have problems with the VR going out because they seem to be using more power with the intercooler fans and control boxes/electronic boost controls gauges. If so, maybe they have less problems because the VR is working not as hard and staying cooler validating the fan solution?

 

[rocket]

Voltage "clamp" circuit

I've been thinking about all this and had an idea. It would be fairly straightforward to create a circuit using a zener diode (set the voltage threshold) and an SCR (inexpensive and high current capacity) to dump the excess voltage to ground. Basically, it would be like a 2nd "backup" voltage regulator and there would be about $5 worth of components in the circuit. Now, it would be more complicated to create something that would be able to operate continuously like the factory regulator, but that isn't the goal. I don't have particular components in mind (other than a general idea), but that is a matter of digging through data sheets to find suitable parts, then prototype and testing. The only other thing would be to figure out how to either fire an idiot light or to shut the motor down (or both).

 

[theshadowrider]

So is the problem with the VR is that they are failing, either do to improper grounding, or overheating, or some other unknown reason, and cause a voltage spike that takes out the ECU? When mine went out the display started flashing the battery symbol and it showed my volts were only one bar. Then shortly after it went out taking my ecu also. It would be nice to have a light come on telling you of improper volts, but I guess it would be even better to make then so they won't fail.

 

[diamonddave]

So is the problem with the VR is that they are failing, either do to improper grounding, or overheating, or some other unknown reason, and cause a voltage spike that takes out the ECU? When mine went out the display started flashing the battery symbol and it showed my volts were only one bar. Then shortly after it went out taking my ecu also. It would be nice to have a light come on telling you of improper volts, but I guess it would be even better to make then so they won't fail.

What we know...

1)Poor grounding. Please add a ground strap from ECM ground (Chassis) to Engine. I added 2, mine is E-start.
2)No Hot grip/tailight fuses. Add fuses. A short to ground in these circuits will pop the ECM.
3)Voltage Regulators seem to be running at a very high temperature. Some have added fans, additional venting.

 

[429dhm]

For those running the small fans, did they hold up for the whole season? I am curious with all the steam and moisture did it contaminant the fans and cause them to seize?

 

[lognomore]

I would say that my fan ran the better part of the riding season and it still works good! If you looked through the rest of the thread you will see pictures if the one I installed. I think there are others that did the same, maybe different but the idea is the same, to cool the ECU. I believe water will not get into the fan as long as you have it mounted in the right direction, that is with the hub of the fan up top.

 

[Eli]

So what is the easiest way to fuse the handwarmers?

Eli

 

[Tellyman]

Wanting to bring this back up, as I had VR and ECU failure this past weekend, on a otherwise trouble free 08 800 with 1800 miles. Just wondering what most of you had/have done. Really don't want for it to happen again, as this time was lucky and not too far in the backcountry. Nothing much for info from dealer. Any input appreciated. Thanks