Electrical problem

[seadoorx951]

I have a 2000 seadoo rx that I just pulled the motor and rebuilt. I put the engine back in and hooked everything up and tried to crank it to check compression and the key wouldn't work at all. I used a test light and had power in the electrical box in the rear. I then grounded out the spark plug wire inside the box and got the key to work but the display on the dash kept blinking on and off. My battery reads 12.37 volts. Does anyone have any idea what could be causing this?

 

[Coastiejoe]

Jump the solenoid. Does it crank or not?

 

[seadoorx951]

Will that work if the key won't engage

 

[Coastiejoe]

There is always power on the battery side of the solenoid. By jumping the large lugs you provide power to the starter.

Without the key/lanyard on, jump the lugs and tell me what happens. It will spark a little. Don't let that alarm you.

 

[seadoorx951]

Ok I crossed it and it cranked.

 

[Coastiejoe]

That means you have a good battery, cables, connections and starter.

On the power side if the solenoid. Do you have additional wires on that lug? On the output side. There should be one wire only.

 

[seadoorx951]

Yes one more wire headed to a plig on the right side of the box

 

[Coastiejoe]

Test your DESS Post..

There are three wires on your DESS post:
1. Solid black wire is a constant ground
2. Black wire w/yellow tracer is the return path to ground for the MPEM circuit that carries ground back to the module
3. White wire w/grey tracer is your low voltage communication wire to the module that exchanges the ROM code in the lanyard


The DESS post is a reed switch, your lanyard contains a magnet and when placed on the post it completes the circuit between the solid black and black w/yellow trace. The presence of a ground back to the module on the Blk/Ylw allows the module to read the code stored in the lanyards ROM chip that is pre-programmed to the MPEM memory. When it recognises the security code it unlocks the ignition circuit and sends the voltage pulses out to the beeper to give you a thumbs up.

To test the post, unplug it and remove it to your bench it's a little easier to probe everything that way. You should have continuity from the solid black wire to the metal ring on the outside shoulder of the post all the time. You should also have continuity from the white w/grey trace wire to the small contact on the very top center of the post all the time.

With the key off the post, you should have no continuity between the black and black w/yellow wires, with the key placed on the post that should complete the circuit and show continuity between them.

There are a few things you can do to test the key itself, clean it first with a q-tip dipped in alcohol and clean any debris out of it and make sure the two side and one top contacts are in place and clean.

You should see continuity between both of the ground contacts in the side body of the key, and using the red test lead on either of the side contacts and the black test lead on the top center contact you should see less than 10 ohms of resistance.

I find any more than 10 ohms on the ROM chip usually causes intermittent or complete failure of the key to work properly with a MPEM module, my programmer will read keys up to about 18 ohms of resistance and program them to modules but the MPEM won't recognise them reliably in normal operation.

 

[seadoorx951]

I will try that when this evening I am not very familiar with the electrical system on these things so that is very helpful thank you!

 

[seadoorx951]

Everything checked out right except my meter read 668 when I tested the black lead on the center contact of the key and the red on the side contact. What does that mean

 

[seadoorx951]

When I do this it completes the circuit. I have a test light grounded to the battery

 

[Coastiejoe]

I can't see what it is you are doing in the pic that completes the circuit?

 

[seadoorx951]

I am touching the test light to the spark plug coil. When I do that it makes the two beeps with the key on the dess

 

[seadoorx951]

I am very confused

 

[Coastiejoe]

I am touching the test light to the spark plug coil. When I do that it makes the two beeps with the key on the dess

Will it crank or start when you do that?

You are power up the coil is basically what is happening. We need to figure when/what powers it and go from there.

 

[seadoorx951]

It won't do anything with the start stop switch. When I press the start switch it makes a quiet clicking noise. As soon as I take the test light off the coil everything becomes disconnected again

 

[seadoorx951]

Ok so I redid my key and DESS test. On the DESS it reads something like 1.5 ohms and the key reads 13 ohms.

 

[seadoorx951]

Alright, I got it to beep and crank with the start stop switch while grounding out the coil like before it will do it repeatedly now. Now I'm wondering if my DESS is bad or if there is a bad ground up front. I'm at a loss

 

[Coastiejoe]

Here is a DESS test with ohms listed.

"Welcome to the seadoo forum 97 spx. I would start by cleaning the Post on the safety lanyard. It is beeping and saying it isn't connecting to the Mpem, (Multi Purpose Electronic Module) It needs to beep 2 times to let you know it is ready to start. Clean the post and cap with soapy water. Don't use any grease of lubricant on it as it needs a clean connection to make contact. Connect the lanyard to see if it is making a connection. 2 beeps and it's ready to fire up.
Here are some advanced test for you.Engine start/stop switch verification;
Disconnect the Yellow/Red wire of the start/stop switch. Using an ohmmeter, connect test probes to the Yellow/Red wire and to ground. Measure resistance, it must be an open circuit (switch is normally open). Depress and hold switch, the ohmmeter should read close to “0” ohm.

Safety Lanyard Switch Verification;
If 2 short beeps are not heard when installing the safety lanyard, disconnect the switch wires.
Safety lanyard removed;
connect the test probes to switch Black and Black/Yellow wires. It’s an open circuit, there should be no continuity.
Connect one test probe to the White/Gray wire and the other test probe to the switch terminal. Measure resistance, it should be “0” ohm. Connect one test probe to the Black wire and the other test probe to the switch ring. Measure resistance, it must be close to “0” ohm.
Safety lanyard on switch; connect the probes to switch Black and Black /Yellow wires. Measure resistance, it must be “0” ohm.
Timer Verification;
The timer is integrated into the MPEM. Always confirm that the fuses are in good condition. To confirm operation of timer, remove the safety lanyard from switch. After 5 seconds delay, depress start/stop button once. The timer should stay on for 33 seconds (for example, the gauge(s) will be activated) and than turn off".