5 amp fuse blowing - 1996 XP

[richardsu]

Hello All,

Hoping somebody out there can help me. The problem I have is that every time I start the engine, it runs for about 1 second then blows the 5 amp fuse in the front electrical box. I have disconnected everything to try and eliminate the problem, including the VTS, gauges, fuel & oil senders, etc, but to no avail. I don't believe it is the MPEM as I had that replaced less than 2 running hours ago, and besides, it makes all the right sounds, ie. two beeps when I plug the lanyard on.

From reading various posts, I have a feeling that it might be the trigger coil or stator shorting out. I've heard the trigger coil brackets on the XP are notorious & fail causing the coil to short out. I've ringed the trigger coil out with an OHM meter and it tests fine, but I heard they can screw with your mind as they will short out to ground once engine is kicking.

Another possibility may be a faulty regulator/rectifier. Is there a way of testing the regulator?

Before I go pulling off the magneto cover to check the stator & trigger coil, I was hoping I could get some confirmation that this is more than likely the problem.

Any comments will be greatly appreciated.

Richard.

 

[seadoosnipe]

Regulator/Rectifier....

Sounds more likely that it's going to be the regulator/rectifier. Your stator and trigger coil should have zilch to do with this. Your blowing the 5 amp fuse to the mpem, which is getting it's power directly from the battery so there must be a surge in power causing this. Blowing this fuse can signify a problem with the mpem also but I'm looking at the other side since you say that this was replaced not long ago. The rectifier receives unregulated AC power from the magneto and converts it to DC power. The regulator holds it to a steady 14 to 14.5 VDC while the engine is running to keep your battery charged.
I'm at work at the moment and can't go into the shop manual but I see your a premium member, so if you go to your shop manual and look under the chapter for the electrical system, you'll see a section on the charging system. I'm pretty sure there is a static and/or dynamic test on checking the rectifier.
Good luck and if you need further assistance, let me know. If you click on my name and look at post's I've answered, you may find where I just sent this test out to another member a few weeks ago. He was having the same problem. It was his regulator/rectifier and replacing it fixed his problem.

 

[richardsu]

Regulator Test

Thanks for the fast response Seadoosnipe. Much appreciated.

Unfortunately, the manual states that due to the internal circuitry of the regulator, no static test is available - only a dynamic test with the engine running. With the 5 amp fuse blowing as soon as the engine starts, a dynamic test is not possible.

I think I'll just replace the regulator and hope for the best. Will let you know how it goes.

Rich.

 

[seadoosnipe]

regulator....

If I remember right, that part wasn't very expensive. Let me know what your results are. There are only a couple things I can imagine it would be and that is either the rectifier/regulaor and the other would be a bad mpem. Lets opt for the rectifier!..........:cheers:

 

[Dennis]

Rectifier

Unplug the rectifier and then see what happens. If the problem is the rectifier the fuse will not blow when it's not plugged in.
DAWG

 

[seadoosnipe]

Testing rectifier

The 5 amp fuse protects your MPEM (multi-purpose electronic module), 15 amp for your starting system. I need to ask a question. When you put your lanyard key on, what happens? Do you get power to the gages? You will only get this power for 33 seconds before the MPEM shuts the power off. If the mpem is allowing functions to the ski, including a start, then your regulator/rectifier is probably bad sending to many amps through the system. No power to the gages or unable to start, may be a sign of a bad MPEM. Simple test; with your battery at full charge, disconnet the plug on your charging system. Start your motor. If it starts and the fuse doesn't blow, then you've found the culprit. The rectifier/regulator. With the charging system disconnected, you won't be sending any power to your battery, so don't run it too long.
Let me know what you find out.

This post goes back a month or so and the person was having the same trouble as you. Try the above quote, as Dennis has also stated.

 

[richardsu]

Problem Solved

Thanks for your advice guys. Unplugged the regulator and she runs like a dream. Have ordered a new regulator. Hopefully will be on the water this weekend.

Once again thanks for all your input. Much appreciated.

Rich.

 

[seadoosnipe]

Thanks to Dennis.

Glad to hear that your mpem was not dead. Now, just replace that rectifier/regulator and you should be on your way!.......And thanks to Dennis for suggesting the idea of isolating the electrical circuit for you to test the rectifier........that early in the morning, my brain wasn't functioning and I had forgot all about it.........LOL........that's my story and I'm sticking to it!.....LOL
Oh, you can order that part from one of the advertisers on the left of our home page for about $50 plus shipping. It's good to know what these parts cost because your liable to find out like me, that a local distributer will sometime have a 100% profit markup.....don't pay to much!....

 

[richardsu]

Joy Short Lived

Got the new regulator on Friday. Pulled the old one out and connected the new. Tried to start the engine and got same problem as before - 5amp fuse blew again literally 0.5 sec after the engine starts. I unplugged the regulator and it runs like a dream.

I left the regulator connected to the stator wires (three yellow wires) but kept the red wire that goes to the MPEM unplugged, started the engine and tested the voltage coming off the red wire on the regulator. I'm assuming I should be getting no more than about 14.5 to 15 volts on the wire. Instead I'm getting about 25 volts. This explains why the fuse keeps blowing. Although I find it hard to believe, it looks like the new regulator is also faulty.

I'm just thinking is it possible that this may be a stator problem, and not the regulator. When I test the stator with an ohmeter, I get 1 ohm between the three yellow wires and infinity between each of the yellow wires and ground - just as the manual suggests. Can't work it out.

Anyway, I'm sending the regulator back for a replacement. If the replacement doesn't work, I'll have to assume it's a stator problem and rip the front cover of the engine off. I'll keep you all informed with my progress.

Rich.