12V Low - 98 GTX

[Bryce GTX]

Hi, many thanks in advance for any thoughts on this one... I've got a 98 GTX with the 12V Low warning and the ski bogs down after running it several minutes.
Things I've checked:
- I checked the battery and tried a battery from a working ski as well. The batteries are charged and working fine.
- I checked the voltages on the MPEM to verify the stator is not the issue.
- I suspected the voltage regulator/rectifier, which unfortunately is built into the MPEM. The guys from OSD Marine for an external voltage rectifier and they didn't currently have the parts to make it.
- I bought a used MPEM for my ski thinking that would do it, but I still have the 12V Low warning.

I'm at a loss at this point... not sure what else it could be? Also, I should note that I swapped out all the old gray hoses and did a new carb kit. The ski runs great for the first few minutes and then once it starts to bog I have to pull the key and put it back on to reset everything.

 

[Ckrawiec]

The voltage output (rectifier) from your MPEM to the solenoid is on pin 3-26, so with a running ski you should see 13.5 volts DC on the red/purple wire back to the battery side of your solenoid.

 

[Bryce GTX]

Thank you for the information!

I ran it on both the MPEM's I have for the ski.
Before starting the ski the volts registered 12.2 coming out of pin 3-26.
Once running these are the numbers recorded over a 20-second period.
12.2, 13.5, 6.8, 13.9, 14.6, 15.4, 15, 14.7, 12.4, 6.5, 15, 15.7, 14.9, 14.8, 15.2, 14.7, 14.9, 14.3
Then back to 12.2 after killed.

I don't know if these numbers bouncing around are acceptable?
I tried the other MPEM and got similar results. Hard to believe the rectifier is bad on both MPEM's.

 

[Ckrawiec]

Hmmmmm....ordinarily I would not have expected to see any voltage on the pin with the ski not running. If my info and understanding is correct....the rectifier doesn't put out any voltage (or any pass through voltage from the battery) until the ski is running since the rectifier is supposed to take in AC voltage from the stator and convert that to DC voltage for the ski and to maintain the battery.

With that said, the jumping around of the voltage is normally indicative of a bad rectifier (and in my manual it says anything over 15V DC says the rectifier is bad) BUT, like you said....I too would find it statistically odd that 2 mpem/rectifiers would BOTH be bad ( the 13.5 to 14 mids look ok, but the 15V+ is concerning).....

Also, point of confusion...your profile say 1999GTX but your post says 1998 GTX (which is correct - not that it makes a huge difference) OR is this a 3rd rogue ski?

 

[Bryce GTX]

Yeah the voltage is only there after connecting the dess key.
It is a 98, I need to fix that on my profile.