2004 gtx constantly killing rectifiers

[Secluesioned]

I have traced everything that I know to do. Heres the list Please read everything and help if you can!

Stator giving 20-75 Volts AC 20ish idle. higher I rev higher it goes. All 3 yellows have continuity between them and none have continuity to ground. So stator seems OK

All wires gone over, removed, and all plugs taken apart looking for corrosion but found none. Cleaned and electric grease used.

Checked all fuses. When I got the ski it had the charging fuse melted. Not blown. But the plastic was melted. I replaced. pulled the pins and squeezed the pins so it made a snug connection with the fuse blade.

Have killed 3 OEM rectifiers. With a new rectifier in it charges 13.6 -13.8. Never goes to 14 with revs.
After 3-4 hours of riding the battery is dead and the rectifier bad.

I can have a new rectifier in had. put it on and get 13.6-13.8 charging (but never increases with revs) and then put the other one on and only battery voltage. no charge. put the new one back on and charging.

I may have found the issue, But need more input. Please see picture. The Plug circled in picture seems to lose connection at times and when the key is put on it does nothing. If it is losing connection while riding, it is not killing the machine. Only ever have an issue when you shut it off and try and start it again. But when it does lose connection you can touch the plug and you hear the sound of a relay click and the ski beeps. The circled wires appear to be the power and ground that go to it? Im not sure. But this is the MPEM and I seen a post on here <<<<<< that explains how to see if the MPEM is bad. From that post it is not. So I am assuming the harness is bad?? But would like more info. Or if anyone reading this has a harness AND mpem they want to sell, Id buy them. But on that I have a question. Does the MPEM replacement require a dealer trip?
I just dont know what else to check on this thing.


Any help would be greatly appreciated. Just trying to figure this out.

 

[mkov608]

I suggest performing the tests on page 562 and 565 of your shop manual. If you're measuring it correctly, your stator output is way too high. The 4-tec upper limit is 25 VAC at 3,500 RPM. See the text below the 45-70 VAC range is for the 947 engine in the DI ski.





If your perform the inductive test as outlined on page 562, and you are over 5 amps, that would explain the melting.

Remember, your are measuring the voltage between phase legs (two yellow wires)



Now on to your MPEM question. No you don't have to go to the dealer to have it paired with your ECU. That's for 2006 and newer skis (I think it started with the '06 year anyway) You can plug a new MPEM in and (if servicable) it will work fine. Just make sure the MPEM is from the same type of ski ... normally aspirated vrs forced induction.

I have had the same problem with my MPEM and I had to replace it. It's probably not your harness; In some cases, that forward connector seems to pull away from the MB inside the MPEM.

 

[Secluesioned]

Thank you for your reply. I have a question. When I tested the stator, I did so with the bad rectifier plugged in. it read like 18vac. Someone told me to test with the rectifier unplugged and I did. Idle is 20ish and I seen it go as high as 50 something with a rev. So should I test with rectifier plugged or removed. I can go test now.

 

[mkov608]

You should follow the shop manual. You test the stator output with the regulator/rectifier disconnected and a special adapter plugged in.

From what you are telling me, it appears your stator is bad ... too much voltage. See my previous post.

You can't test the stator with the regulator/rectifier plugged in; in that case, you are testing the regulator/rectifier, and if you are getting 18 VAC, you have other issues. Stator output is AC; regulator/rectifier output is DC ... think full-wave rectification.

 

[mkov608]

You need this harness to perform the steps in the shop manual.

Motorcycle Parts

Additionally, did you check the three wires from the stator like this:

pins 1 to 2
pins 1 to 3
pins 2 to 3

???

Tell us what the resistance values are. "They have continuity" doesn't work.

In the '04 manual they only have you checking two connections not three. The procedure is more mature in the '05 shop manual

 

[Digdog]

Charge the battery with a normal charger at 2 amps for at least 6 hours and let it rest for an hour or two then test the voltage of the battery.

 

[Secluesioned]

@mkov608 The resistance of them are all in spec. around .4-.9. I will check again though. And is that harness a must or can I just use my snap on multi meter to verify VAC? Again, Thank you for your help. Seems like you are the first one to sound like they know something lol.

 

[mkov608]

Yes the harness is a must; it puts a load on the stator. It also keeps you from having a potentially large explosion/fire in the hull. With the stator disconnected and the engine running, the stator is producing about 380 watts of power just looking for a ground. When if finds the ground, you'll get a very nice spark that is capable of igniting any fuel vapors that may be lingering in the hull.