1997 GTX - Simply shut off! Electrical?

[trueheart]

Hey everybody, I'm new to this site. So thank you to any help I might receive.

2 days ago, my GTX shut off while running at about 25 mph. I checked fuses and found the fuse in the rear (next to battery) to be blown plus a wire had broken coming out of the fuse casing. I repaired the wire and replaced the fuse. It started right up and ran fine. Yesterday, while touring for about an hour, was traveling at close to 50 mph, hit a decent size wave, so the GTX got a small jolt, and the engine simply died, as it did before. I suspected a fuse problem again, so I checked all three and all are fine. Any ideas on what to look at next?

I will add that the plastic box in the rear on the GTX had some water in it, about an inch, probably from last year activity when I got water inside the boat and the seal was not seated properly. There is a little bit of corosion going on inside this box to a couple of the electrical connections, likely due to the moisture condition.

Anyway, I am reading that possible culprits could be the rectifier or MPEM. Any ideas on how to nail down the exact problem?

Thanks, Steve

 

[ski-d00]

you need to explain clearly what it is doing when you put the key on, when you press start, etc., any noises, clicks, number of beeps, etc. then we can help.

 

[ski-d00]

although, I suspect pick up coil right away breaking off by the impact.

 

[trueheart]

To Ski-d00,

Thanks for responding! When I put the key on, I get nothing ... no beeps and nothing on the instrumentation. It is as though it has no electrical power at all.

Steve

 

[trueheart]

Sea-d00,

When you say "pick up coil", can you explain what this is, where it is located in the GTX, and how I might go about checking it?

Thx, Steve

 

[ski-d00]

Well, no beeps and no gauges means we have to first see if the mpem is getting power. check fuses on the mpem first then trace the red/purple wire from the rear black box and make sure 12v is leaving the rear black box and getting up front to the mpem. my guess is you still have a bad connection. probably not mpem or rectifier.

if you press start without the key on, do the gauges react?

 

[trueheart]

To Sea-d00:

I traced the power from the rear to the front electrical box. Power is present just before going into part (black jelly covered) that is 6.5 inches long, by 4.5inches wide, by one inch deep ... electrical module assembly? inside of gray box. No power coming out after 5 amp fuse. Found that the 5amp fuse had blown, and when I went to replace it, just blows again, and key is not on. Won't accept the fuse without blowing.

When I press the start button without key on, I get no response from any guages.

Thanks for your help.

Steve

 

[ski-d00]

that black epoxy potted (jelly covered i think you called it) electrical part is the MPEM(the brain).

you have a dead short and I supspect it is in the mag/pick up area. unplug the gray plug on the mag cover(very front of engine), then replace the 5A fuse. I expect it not to blow and you'll get your beeps and gauges but, of course it won't run.
if all above is true, you need to remove mag cover and inspect. I think you'll see the problem right away as I said previously I expect it to be a broken pickup, but you never know. just have to systematically trace the problem.

On a side note, I am giving you the beginner's way to find your problem for people without the proper tools and equipment. I personally would use my mag pigtail and check the wire resistances and know right away if it was in the mag area. but anyway, we'll still end up with the same diagnoses but it may take a little longer and you may waste a few fuses.

 

[trueheart]

Sea-d00,

I did as you said. Interesting. The mag contact points look ok to my untrained eye. There isn't any scorched areas. Looks fine. And when I put the 5 amp fuse in, it doesn't blow, but the starter comes on the moment I put the fuse in and the engine turns over ... continuously.

What is next step?

BTW, my email address is stevetrueheart@gmail.com if that would be easier for you.

Thanks,

Steve

 

[ski-d00]

Well, it's grounding back through the MPEM so we should figure out where the short is. Open the rear black box and disconnect plug from the solenoid. Put the 5A fuse back in and see if it cranks. Check resistance between all the leads that go into the mag case and verify that you have a dead short to ground on one of the leads.

The problem isn't with the mag contact points at the plug, it's what's inside causing the problem.

 

[trueheart]

With mag still unplugged at front of engine, unplugged lead on top of rear box, inserted 5 amp fuse. Nothing happens. Starter does not engage.

Check resistence?

 

[ski-d00]

don't unplug the lead on the top of the black box, just the solenoid plug which is inside, it's the thing with both the red battery terminals bolted to it, should have a 2 wire plug attached to it at the bottom, just unplug that.

 

[trueheart]

Ok, did that. There is some water inside that connection, both male and female sides. Remember I had water, about an inch, inside the plasitic box. So some of it got inside this connection. With it unplugged, and mag at front of engine also unplugged, I put the 5 amp fuse in and got nothing.

 

[trueheart]

Sea-d00,

I had a couple of exchanges with "all things custom" during last weekend. Told Mike about my problem, and he instantly thought it was the MPEM. However, I just wanted to go through the step by step diagnosis (with your help) to narrow the exact problem down. I plan in the future to take my jet ski to Baja, Mexico and I won't have access to Seadoo techs down there ... I will be forced to deal with issues on my own. So the current situation is a good test for me. Also, I guess I'm not 100% convinced that it is the MPEM, since I had the corrosive problem and broken wire in the rear electrical box just prior to experiencing the 5 amp fuse blowing problem. Anyway, I was enjoying getting your helpand looking forward to isolating the problem. If you don't have time, I understand, just let me know. Thanks, Steve

PS. Does the 5 amp blowing problem always mean MPEM is the culprit?

 

[ski-d00]

It could be MPEM but I wouldn't suspect it first. You should check the resistances of the stator and coil first. I still think you snapped off the bracket of the pickup coil due to the impact and it shorted out, it's a common problem.

5A blowing doesn't always mean the MPEM is bad. I'd do the elec tests first and then pull the mag cover off and take a look. You should get a shop manual, there free here with Premium membership or buy a cd copy for a few bucks on ebay. it will explain the elec test for the mag/coil.

 

[trueheart]

The problem with my Seadoo was the MPEM. I removed it and sent to Mike at "All Things Custom". He repaired it and sent it back to me, which took a little over a week. I reinstalled yesterday and my Seadoo fired right up. A big thank you to Mike at "All Things Custom" for a prompt repair and a less costly solution as opposed to buying a new MPEM!

Just FYI, but this was the second time I dealt with an MPEM problem. I am the original owner of this GTX. The first problem occurred in 2004, so I got 7 years out of the original part. I replaced the bad MPEM in 2004. My second MPEM problem occurred this July.

 

[norcalatver]

Hey everybody, I'm new to this site. So thank you to any help I might receive.

2 days ago, my GTX shut off while running at about 25 mph. I checked fuses and found the fuse in the rear (next to battery) to be blown plus a wire had broken coming out of the fuse casing. I repaired the wire and replaced the fuse. It started right up and ran fine. Yesterday, while touring for about an hour, was traveling at close to 50 mph, hit a decent size wave, so the GTX got a small jolt, and the engine simply died, as it did before. I suspected a fuse problem again, so I checked all three and all are fine. Any ideas on what to look at next?

I will add that the plastic box in the rear on the GTX had some water in it, about an inch, probably from last year activity when I got water inside the boat and the seal was not seated properly. There is a little bit of corosion going on inside this box to a couple of the electrical connections, likely due to the moisture condition.

Anyway, I am reading that possible culprits could be the rectifier or MPEM. Any ideas on how to nail down the exact problem?

Thanks, Steve

Where are these 3 fuses located? I am thinking of buying a 1997 GTX from a buddy. He parked it 2 years ago and now it has no signs of power. He replaced the battery so I know that is not the problem. I found the 15A fuse right by the battery. Where are the other two? This thing ran great when it was parked, so it is confusing as to why it all of a sudden has no power to gauges or anything.
Thanks and sorry for hijacking youe thread

 

[trueheart]

fuses in nose

Hey Norcalatver:

The other fuses are in the nose. You need to lift out the plastic liner then you should see a gray plastic box mounted on the side, which contains the MPEM (brain) for the GTX. There are two fuses inside this box attached to the MPEM ... a 15 amp and a 5 amp. Good luck and let me know if you need more help. The 97 GTX is a real good older jet ski. It is worth your time to get it running.

Steve Trueheart

 

[norcalatver]

Hey Norcalatver:

The other fuses are in the nose. You need to lift out the plastic liner then you should see a gray plastic box mounted on the side, which contains the MPEM (brain) for the GTX. There are two fuses inside this box attached to the MPEM ... a 15 amp and a 5 amp. Good luck and let me know if you need more help. The 97 GTX is a real good older jet ski. It is worth your time to get it running.

Steve Trueheart

Thanks Trueheart,
I found the fuses and all are good. Amazingly, everything under the hood and seat looks alsmost new. I know the mpem was replaced 5 years ago and it is new. I just have no clue why there is no apparent power to the ski. It has a new battery and when I put the lanyard on, absolutely nothing happens. This ski ran when it was last parked years ago. Thanks for your help!
Dave

 

[timmyboy76]

at the relay, theres a 15amp fuse also, check that, and clean with eraser, the post and landyard?

 

[trueheart]

Norcalatver:

Do you have a voltage tester of some kind? I found it helpful to trace power through the wiring ... helped me narrow the area of the problem. If you don't come up with the answer on your own, I would recommend detailing your problem to Mike at "All Things Custom". He is very knowledgeable about electrical problems with older SeaDoo jet skis, and can probably help you.

You said the battery was new, but did you test it or have it tested for voltage strength?

Lastly, you said the MPEM was replaced 5 years ago. Coincidentally, that is 2004, the very year I replaced my original MPEM, and that replacement MPEM just went bad again this year! Mike repaired it though!

Steve