97 GSX (787) electrical troubleshooting

[93XP+96GSX]

Hello,
This is my first post. I just bought a 97 GSX with the 787 motor and a 93 XP with the 657 motor. Neither of them run. I have mechanical experience but limited electrical experience and I have some questions. For the sake of brevity I’ll be starting another thread regarding the XP soon.

The GSX:
The thing is completely lifeless. I can jump the starter solenoid and it turns over but nothing happens whatsoever electrically. I checked all fuses and they were good.

I’ve never had one before so I’m not familiar with what it’s supposed to do but from what I’ve read it should beep twice once the dess key is placed on the post, and the gauges should light up when the start button is pressed regardless of the key.

I’ve tested the start button and it is good.
The buzzer was no good, but I have one that works well when 12v is applied directly to it. Even with this one hooked up I can’t get any beeps. I cleaned up the contact surfaces of the key and post and still no beeps.

I performed the following tests on the DESS key and post.

With the switch wires disconnected, and the safety lanyard removed:

1.Black + black and yellow = no continuity
2. White and grey + switch terminal= 0.1 ohms
3. White and gray + ring on switch = no continuity

With lanyard on the post:

1. Black + black and yellow = rapidly fluctuates between 15-350 ohms

On the DESS key itself:

1.Between the side contacts of key: 0.1 ohm

2.Between side contact and center= no continuity.

Some of these match what the manual says they should be, but some don’t. I’m just not sure how to interpret the results or whether the ones that are abnormal are due to the key and/or post or the MPEM.

I Also found that the VTS motor was unplugged. I tested it and it’s no good.

I suspect the MPEM is bad. Of course this year and model uses the unique plug in style mpem and CDI module and I can’t find any information on how to test it anywhere.

My main questions:

1. how can I test the MPEM on this to know if it’s any good?
2. Should I leave the VTS motor unplugged or plug it back in?
3. What else can I try?

I attached images of the VTS motor, the rear electrical box, and the MPEM.

Thank you

 

[POPPS]

The vts motor is unplugged because it blows its fuse, either the motor is seized, or the module is fried.
Just set the nozzle by hand and leave it.

 

[93XP+96GSX]

The vts motor is unplugged because it blows its fuse, either the motor is seized, or the module is fried.
Just set the nozzle by hand and leave it.

@POPPS The motor is seized, It did nothing when I applied 12V directly to it. Thanks for your response!

 

[artr]

So do the gauges light up if you just press the start button with no key on dess? If so that indicates the MPEM is reponding. If not check that 12V and ground are getting to the MPEM.

 

[93XP+96GSX]

No, with the key on or off I have yet to see the gauges light up.

So do the gauges light up if you just press the start button with no key on dess? If so that indicates the MPEM is reponding. If not check that 12V and ground are getting to the MPEM.

Prior to viewing the diagram I tested the red and black wires running to the rectifier on the mpem and got 12v. I’m honestly not that great with wiring diagrams, do you know which wires I should be checking to confirm it’s getting power? I’ll attach the diagram.

 

[93XP+96GSX]

I can see where the diagram says 2-18 and 2-19 and understand that means connector 2 numbers 18 and 19 but I’m not sure how to find 18 and 19 since they don’t appear to be numbered in order unless some of the holes are skipped over

 

[artr]

That is the wrong schematic for a 96 GSX.

 

[93XP+96GSX]

It’s a 97, when I bought it I was told 96 but I found out it’s a 97 and can’t change my profile name. This is the MPEM.

 

[artr]

It looks like the main power for the MPEM comes in on connector 3. Use the wire colors to find what you need from diagram. You can start in the rear electrical box. The red-purple stripe wire is 12V and the black is ground. They run to connector 3.

 

[93XP+96GSX]

It looks like the main power for the MPEM comes in on connector 3. Use the wire colors to find what you need from diagram. You can start in the rear electrical box. The red-purple stripe wire is 12V and the black is ground. They run to connector 3.

Thank you! I’ll check those for power and continuity tomorrow.

 

[93XP+96GSX]

It looks like the main power for the MPEM comes in on connector 3. Use the wire colors to find what you need from diagram. You can start in the rear electrical box. The red-purple stripe wire is 12V and the black is ground. They run to connector 3.

I checked and got 12V from the red/purple (3-26) using the black (2-24) as the ground.

 

[artr]

The ground from the rear electrical box runs to 3-17. Check at the back of connector 3 that you get 12V across 3-26 and 3-17. If you can not get the meter on the wires on the back of the connector, you can carefully insert a straight pin into the back of the connector to make contact with the wires.

 

[93XP+96GSX]

The ground from the rear electrical box runs to 3-17. Check at the back of connector 3 that you get 12V across 3-26 and 3-17. If you can not get the meter on the wires on the back of the connector, you can carefully insert a straight pin into the back of the connector to make contact with the wires.

I can get it across 3-26 and 3-24 but this is what I get with 3-26 and 3-17

 

[artr]

I can not clearly see your reading clearly but I think you are only getting a fraction of a Volt where you should see 12V. You do not have a good ground to the rear electrical box. You should use your ohmmeter to check between your battery - post and 3-17 from the connector. If it is not 0 ohms then you probably need to clean up the connection between the battery- and the starter (large black cable), most likely at the starter. You should measure 0 ohms from 3-17 to any bare spot on the engine block or the battery negative.

 

[93XP+96GSX]

I can not clearly see your reading clearly but I think you are only getting a fraction of a Volt where you should see 12V. You do not have a good ground to the rear electrical box. You should use your ohmmeter to check between your battery - post and 3-17 from the connector. If it is not 0 ohms then you probably need to clean up the connection between the battery- and the starter (large black cable), most likely at the starter. You should measure 0 ohms from 3-17 to any bare spot on the engine block or the battery negative.

I have continuity from the negative post of the battery and all the bolts on the engine, however I have no continuity between the post of the ignition coil where all the black wires are ran to, I’m assuming those are ground wires. I can’t seem to find where the rear electrical box is grounded to.

 

[artr]

The rear electrical box receives ground from 3-17 on the MPEM. Do you have continuity between battery negative post and 3-17 on the MPEM connector? If you do then you need to remove the bolt at the base of the ignition coil where all the black wires are connected. Clean up any corrosion on the bolt and the ring connectors on the black wires that attach to the bolt and reassemble.

 

[93XP+96GSX]

This morning I removed the ignition coil and cleaned the posts of the coil and all ring connectors and put dielectric grease on them. They were pretty corroded, however, still no continuity between 3-17 and the negative post of the battery.

 

[93XP+96GSX]

It appears 3-17 runs to this connector before the electrical box. I get no continuity between the 3-17 terminal on the mpem and any of the wires on this plug. It looks like it runs straight to here, should I cut the wrapping off it and check for a break somewhere?

 

[93XP+96GSX]

what I don’t understand is I do have continuity between the black wire in this plug and 3-17. There’s also continuity between this black wire and the negative post of the ignition coil?

 

[artr]

what I don’t understand is I do have continuity between the black wire in this plug and 3-17. There’s also continuity between this black wire and the negative post of the ignition coil?

The only black wire on that connector is the one from 3-17 plug on MPEM. It sounds from what you are saying above is the connector is not making contact when connected. Look at the internal pins of that connector and clean up with contact cleaner or alcohol and reconnect. You need to track down why the ground on 3-17 does not make it to the base on the ignition coil.

 

[93XP+96GSX]

The female end (end coming from the mpem) of the black wire looks a little off compared to the other ones. I assumed they would pull right out of this connector but they won’t go any further than this?

 

[artr]

I have never taken one apart. There is a tool that is a hollow tube that fits over the female or male ends and collapses a couple of barbs that keep the ends in the connector body, then they will just slide out of the connector body. If the wires are making contact with the male or female ends, you should be able to clean them up by gently scraping them with a stiff wire or paper clip and rinsing off with alcohol.

 

[93XP+96GSX]

I was mistaken, that’s the wrong plug. The one the diagram shows running to 3-17 is this plug at the electrical box. The diagram shows two white wires on this plug however it’s two black instead? I’m gonna check the connection there now.

 

[93XP+96GSX]

Okay I cleaned that plug up, I have continuity from the ignition coil to 3-17 on the mpem. Still nothing between 3-17 and the battery or engine. Also nothing between the coil and the neg post of battery or the engine.

 

[93XP+96GSX]

This ignition coil looks pretty rough.. could this cause a disconnect between the engine ground and the mpem ground?