1998 GTX LTD - Electrical Issues

[Twobit]

Good Day All,

A mate of mine owns a 1998 GTX LTD which overheated due to a non-functional beeper about 18months ago. The PWC went to a Seadoo Mechanic who remade the wiring harness (took 18months) but now it does not really do much (see below). Obviously, there is so much unknown with what he did...

From what I can tell with the service manual, all the cables seem to align up. Brand new fully charged battery. If you manually trigger the solenoid the engine cranks.

There is just no lights or gauges at all; or beeps (new beeper installed). Cannot work out if in MPEM programming mode after 5 pushes as no beeps.

So far, I am looking into why the RPM shows 1000 when the DESS key is fitted and you hold START. Seems like there may be a cross wire between the RPM sensor and START button?

Without the DESS Key:
Push Start - Nothing

With the DESS Key:
Push Start - RPM gauge climbs to 1000 RPM

Any thoughts or suggestions on what to look for with the RPM?

PS: I have read many similar stories caused by the missing ground from the coil and have checked that. There is 12V getting to the MPEM but the Voltage to the Dash is 0.72 when measured over the 25/26 pins (Plug 1); P1 Pin25 (GND) is has continuity to P3 Pin 24 (from engine/starter ground). So there does not seem to be power delivered from the MPEM to P1 Pin 26, which is logical if there is an issue with the start?

Regards
Twobit

 

[SabrToothSqrl]

Well..the beeper doesn't actually cause over heating... so... was everything that was cooked also replaced?

When overheated, the engine block likes to turn a grey/gold color. Especially the exhaust manifold.

at 19 years old... it may be better to invest any funds into a newer ski...

have you been able to check the compression of the engine? was the root cause of the overheat issue found and corrected?

Usually an overheat cooks the engine - the electrical parts remain fine. Do you have photos of what happened?

 

[mikidymac]

I wouldn't trust some hack re wiring the ski. I would buy a good used harness from [MENTION=41828]Minnetonka4me[/MENTION] or else you will spend all summer chasing this mess. Also as squirrel said you need to fix the overheating issues.

 

[Twobit]

Thank you to both of you (SabrToothSqrl and mikidymac) for taking time to reply to me. I do apologies, I have zero JetSki ski experience (never ridden or even started one).

The root cause of the heating issue was debris sucked into the cooling intake, with a fault beeper not alerting the driver to the situation.

The Mechanic did all the "required" repairs and testing on the engine. If you apply a low voltage 12v input to the solenoid the engine runs well. During his repairs he noted some wiring damage, was unable to source a harness locally (Australia) and ended up making some modifications.

I will most certainly start with the suggestion of a new harness and while waiting; I will take a look at the RPM Sensor wires and Start/Stop wires as I suspect his "custom harness" must have swapped them around as this is the only logical explanation (to me) why the RPM need would move if the Start/Stop is held.

 

[Twobit]

So it seems I was mistaken, it is not the RPM moving but rather the Speedo. With the DESS key fitted, holding start and the Speedo climbs to the first 10; release the start button and it goes to zero.

Without the DESS key nothing when holding the Start.

In terms of the DESS post, tests seem normal with expected results with key on and off.

Zero beeps with a new beeper installed.

 

[XP 787]

With out the Dess key installed push the start button 5 times, do the gauges power up? Still trying to figure out how the ski ended up with electrical problems from over heating.

 

[Twobit]

Hi XP787, 5 pushes and nothing.

I am also unsure of what exactly occurred - I am away from the JetSki until 2 May. I will try get more details from the owner. Its very confusing.

 

[jjsinaz]

If you have not done so already, download the service manual and print out the wiring diagram. Sounds like you are going to need it to figure this out.