protecting the ECU?

[LeftField]

A couple more data points (warning - engineer nerd at work):

I hooked an oscilloscope up to a couple of the orange wires going from the regulator to the ECU. The regulator output was a +/-15V trapezoidal output (sort of like a square wave). I can provide the exact wave form if someone is interested. The frequency at idle was 180Hz and it increased with engine RPM. The voltage levels remained unaffected. A person might be able to use back-to-back zeners between each of the three wires, which is a fairly common approach, but there is risk of murphy getting involved.

Regarding grounds, I found the same thing as 'mn2mtns' - the electronics plate is not grounded to chassis. This appears very intentional as all fasteners between the two plates are rubber and electrically isolated. This seems to be validated by the fact that the chassis ground point has been placed on the belt guard, not the electronics mounting plate.

I also looked at the ignition design; similarly it also does not depend on any ground between the engine (sparkplugs) and the coil frames or chassis. The two coils are wired in series, both plugs fire every half revolution. The high voltage path is also in series which allows operation with complete electrical isolation between the engine and the electronics.

FWIW, while 'floating' (not tied to chassis ground) circuitry is unusual in automotive applications, it is fairly common in applications that are exposed to high levels of electrical noise. It allows the electronics to rise and fall with the spikes rather than try to constrain it or withstand it. An analogy might be a boat freely floating on the waves as opposed to being tied rigidly to a dock - risking either being swamped or ripped loose. A good question is whether it is working the way Polaris intended...

I'm a coward regarding tampering with something I don't fully understand so my strategy will be to pursue improved cooling. I put a thermocouple on my ECU this morning and monitored it while I did my voltage testing - within just a few minutes the regulator had risen to 125 degrees - with the cover off, hood up and outside temperature of 45F. I will monitor it during my next ride, but would guess that it gets very hot during normal ops. In my experience with reliability of electronic designs, 125F is plenty warm already.

I plan to raise the capacitor by 3/4" and install a CPU fan between the cap and regulator blowing down on the regulator. I will get post the 'fan' mod regulator temperatures and pictures following installation.

Tim

 

[ruffryder]

A couple more data points (warning - engineer nerd at work):

I hooked an oscilloscope up to a couple of the orange wires going from the regulator to the ECU. The regulator output was a +/-15V trapezoidal output (sort of like a square wave). I can provide the exact wave form if someone is interested.

please proved the wave form that would be interesting to see. So it is a trapezoidal output with a positive peak at +15 volts and a negative peak at -15 volts so a peak to peak measurement of 30 volts? I wouldn't think that would be the case as a rectifier being involved should keep it all positive. I question this, a picture of your plots would be nice and appreciated.

The frequency at idle was 180Hz and it increased with engine RPM. The voltage levels remained unaffected.

That makes sense at it is driven by a stator / magnet assembly. I would imagine the frequency is dependent upon the number of poles and the rpm at which the generator (stator / magnet) is turning.


I assume this is a working regulator / rectifier? Cool stuff!

 

[LeftField]

Regulator to ECU - orange wire voltage waveform

Hopefully I've figured out how to attach a picture correctly. I sketched it as my scope can't do screen capture.

The parts should be good - sled is running fine anyway. I'm wondering if the regulator is providing regulated 3 phase +/-15 volts to the ECU, and the ECU is actually doing the rectifying and filtering of its own internal power.

Looking at the schematics, it shows that the ECU also gets power from the 'Regulated Power' splice (which is the 12V source for chassis power just upstream of the chassis relay). Not sure if it using this for power or just monitoring it.

The ECU's 12V return path ties back to ECU Ground then to the Chassis Ground; it is made through wiring instead of through the ECU or regulator housings which are floating wrt chassis.

It would be interesting to measure currents on the connections between the regulator and ECU but don't want to insert an ammeter as a bad connection could cost me a few hundred bucks...

 

[ruffryder]

anyone have a schematic they can post up? It would like to be able to see what all is connected to where.

good quality, so that I can print it out would be nice...

LeftField, you mind taking a look at what the signal looks like before the regulator. I would assume it would look pretty close to a sine wave. Just trying to make sure my assumptions though.

 

[BIGGDAWG]

anyone have a schematic they can post up? It would like to be able to see what all is connected to where.

good quality, so that I can print it out would be nice...

LeftField, you mind taking a look at what the signal looks like before the regulator. I would assume it would look pretty close to a sine wave. Just trying to make sure my assumptions though.

you can download the manual here

http://www.snowestonline.com/forum/showthread.php?t=182549

 

[skibreeze]

I got a new ECU today and will get it out Sun and Mon if all goes well. I cut out the foam under the ECU where the holes were at. I didn't take it all out thinking that some will be good for vibration damping. I also removed the capacitor from above the vr and mounted it to the outside of the plastic electronics cover right next to the spark plug holder. That should help cool the vr more. We'll see how it all goes.

 

[ruffryder]

you can download the manual here

http://www.snowestonline.com/forum/showthread.php?t=182549

well, I found out were the problem is... your wiring diagram isn't in color. No wonder there is a problem!

ha ha

I have to say though, my yamaha manual is much better, especially the wiring, and it looks like the polaris sleds have a lot more stuff attached to them.

Anyways, interesting how there is a regulator on the clutch guard and then there is another regulator for the ecu? Says it is a capacitor? That is interesting. Especially with the results that we have about the square wave type output. If you put a capacitor on it well, that would smoothe the wave form out a little bit wouldn't it? You wouldn't have the squareness of a wave form. I have a hard time believing that the ecu would take the waveform and regulate / rectify it inside. There is a reason the regulator / rectifiers are pretty big. It is because they are a heat sink for when they dump energy to try and keep the voltage constant. I mean, aren't the things just giant heat sinks?

Does that make sense to anyone?

 

[skibreeze]

Ruffy, the cap is to store energy on the first pull to power the electronics so the sled can start.

 

[ruffryder]

Ruffy, the cap is to store energy on the first pull to power the electronics so the sled can start.

cool, that still doesn't makes sense when compared to the output that is squared.

Thinking about this some more, that cap wouldn't do anything if the output of the regulator was anything besides a DC output. Any waveform, well most anyways, average to an output of 0 volts. Therefore, that is what the voltage on the capacitor will be when the source is disconnected.

I now HIGHLY suspect the output of the regulator/ rectifier that has been shown.

 

[mod03rmk800]

Can add my 08 dragon 800 to the list of the 'smelly black smoke' issues.
BUMMED!

 

[Polar Express]

Thanks to all of you working on this problem, and sharing the progress with the rest of us! I appreciate it!

PE

 

[WestMont]

Thinking out loud and not sure if there is any value in what I noticed when when mod03's ecu failed but here goes.
He had just finished taking a 5-10 minute break, started the sled and dropped down on a groomed trail, slowly rode down the trail maybe a mile, then he left the trail and started down a creek drainage when about the time he was going to cut up the hill to his left (going from lower rpm's to wot) the engine started to fumble so he shut it down. After the engine was shut down he noticed smoke coming out from under the hood (plastic cover on clutch and said he thought it was on fire).
Reason for even mentioning that is I was just curious if there is any pattern of when the vr/ecu's fail? For example has anyone had one fail in the middle of a climb (wot) where you don't or can't just shut the sled down but when it does quit you now have another issue with the sled rolling back down the hill or do they most often fail at lower rpm's?
Maybe his case was he had been riding (ecu hot but had air flow coming thru the hood vents to help aid in cooling it and the capasitor) but when he stopped for a break the capasitor and or the ecu even got hotter even if it was a short time because the under hood heat increased without the air flow from moving. After cooling some from taking a break but not being able to cool much because they are covered up by the plastic cover and then slowly riding down the trail did they simply over heat and it had nothing to do with throttle position persay(different throttle positions varying voltage and or currant). Or was it one or more of the before grounding, not grounding, voltage spike, etc.... issues that was mentioned before which make the most sense.
After removing the ecu and holding it with the electrical pin connectors down and the gel filled back facing you it was bubbled up and pressure was released (gel split open) in the top left corner. If looking at the aluminum plate that the ecu is bolted to you could see a black residue left on it also.
With all of that said his was obvious that the ecu burned up but my question is there any perticular pattern to the failures?

 

[Kleiny]

I was working on my sled and noticed a problem area. on the power valve controller the 2 wires going into it had about 3/8 of an inch of wire exposed on both leads. It looked like the insulation either shrank or slid up away from the controller . the wires are close enough to touch . My first reaction was that it was a fluke but I checked my other 08 dragon and it was pretty close to the same. If the wires do touch , I'm wondering if that is a big enough short to cause a voltage reg. & cpu melt down. I will take some pics and try to post them tommorow .

 

[ruffryder]

You washington guys, should we have a EE nerd fest / electrical garage session? My garage is full, and I don't have an O-scope, but we could get a list of test to do and knock them out.. Maybe drink some beers in the mean time as well.

I would be down.

 

[jim9006]

You washington guys, should we have a EE nerd fest / electrical garage session? My garage is full, and I don't have an O-scope, but we could get a list of test to do and knock them out.. Maybe drink some beers in the mean time as well.

I would be down.

Add me to that list... Hell I'd even bring the beer...

 

[sam776]

Another one up in smoke

We were riding on Friday, had a friend from California that had never ridin, put him on my 08 800 163, and I rode a buddys Doo. As we pulled up to stop I thought I saw the headlight fail, but wasn't sure. We went to take off the D8 wouldn't start, checked spark and it was ok, plugs looked dry. Finnally put alittle fuel in the cylinders, fired up, went about 1/4 mile, quit for good. Opened the hood to burning wire smell, and a 15 mile tow out. Its at the dealer now, I guess we will see what they say

 

[growl62]

Another one bites the dust

Add my buddies D8 to the list of failed VR and ECU. (Still waiting dealer confirmation) We rode this morning for all of about 30 minutes, before it failed. We were on an easy juant up an old logging road and stopped for a minute. When he started it back up, it promptly died. He tried for several minutes to re-start, but no luck. We were finally able to get it to start, but smoke started coming out from under the electronics cover. We shut it down and pulled the cover.
I have a degree in electronics, but by no means am I educated to the level of an EE. I did some basic trouble-shooting, but found nothing obvious. The only thing for sure is that the magic smoke had been released from the ECU. I towed him 10 miles back to the truck.

As a side note of interest, his sled did smoke something gawd aweful when he started it up in the morning. We're not talking the usual amount of smoke, but much more. It eventually cleaned up and seemed to be running fine.

I, like most of you, don't have a warm fuzzy about this issue. Had my friends sled made it a couple more miles, we would have been down in the depths of "no towing out hell!" Also, given the number of posts on this topic, it's a major issue and I hope Polaris, or one of you electronic gurus can figure it out.

Thanks for your efforts.

 

[diamonddave]

Are any of these latest failures Electric start?

 

[WestMont]

As for mod03's his is not an electric start.

 

[GMCRMK]

Is this limited to just 800's or are 700's up in smoke too?

(If it was mentioned earlier sorry)