95 spx DEAD. NOTHING. keep blowing 5amp fuse

[JesseTopp]

I installed a new VTS computer in my 95 spx. It started up an ran fine. It quit and when I went to re-start it the machine was dead. It was like there was no battery in it. I went an installed a brand new battery, charged it-still nothing.
I took the box back apart and seen I pinched one of the purple wires. I taped it back up and tried again. Dead. not a thing.
Took it back apart jump the solenoid. Turned over great. Check fuses and the 5amp was blown. Replaced it and as soon as I hooked up power it blew?

Back to nothing but that at least narrows it down a bit. I bought this machine for the kids in my family to enjoy this summer. Just wanted something reliable and safe for them. Any help is much appreciated.

Thank you

 

[GGuillot]

Does it still blow the 5 amp fuse with the VTS disconnected?

 

[JesseTopp]

Havent tried unhooking it yet. Just disconnect all wires going into VTS. I took the box apart to replace the VTS
Pinched a purple wire but it seems ok now. Just took the outer coating off. Heat shrink wrapped it back up.

 

[mikidymac]

Try it without the VTS.

 

[PolarCelsius]

Definitely disconnect the purple wires within the MPEM box AND the wires connecting to the VTS up-down buttons from the handle bars, there should be a connection for it underneath the front storage bin, you may have to take off the plastic handlebar cover to wiggle and identify the wires

This effectively takes your VTS out of the equation, which is hopefully whats blowing your fuse, as this is the case on my 95' XP, you'll just have to live without the VTS (not really important, just angle the nozzle where you want it and it will serve you)

THE BAD
When I first got this XP, it would immediately blow the 5 AMP fuse but not just because of the VTS, but also because the MPEM was FRIED from the previous owner using a jump pack on the battery while it was still connected to the MPEM box. I dont want to cry wolf just yet but having your 5 AMP fuse blow immediately is a direct symptom of a bad short within your MPEM which means you need a new MPEM

I recommend finding a used and known working OEM MPEM from eBay, I found mine for $70-ish

Here is the wiring diagram I used for my 95' XP It may be similar to your SPX
Along with a link to my thread about trouble-shooting my MPEM

 

[etemplet]

Check the MPEM. Disconnect the red wires from the MPEM. Hook one side of your multi meter to the black ring terminal and the other to the red ring terminal. If you have continuity the MPEM diode is blown. How do I know?? I actually made 2 test mpems with the diodes connected outside the MPEM what way if it blow I can replace it easily.

Failure cause on my SPI was the rectifier. It fried the MPEM while I was riding hard.... bam.... nothing !!! Dead in the water. Good Luck

 

[PolarCelsius]

Check the MPEM. Disconnect the red wires from the MPEM. Hook one side of your multi meter to the black ring terminal and the other to the red ring terminal. If you have continuity the MPEM diode is blown. How do I know?? I actually made 2 test mpems with the diodes connected outside the MPEM what way if it blow I can replace it easily.

Failure cause on my SPI was the rectifier. It fried the MPEM while I was riding hard.... bam.... nothing !!! Dead in the water. Good Luck

View attachment 48069View attachment 48070

Care to elaborate on reviving an MPEM suffering such a fate? I have one sitting around that has that same diode blown

 

[etemplet]

Look at the pictures closely. I couldn't find any details I needed to identify the diode. I just dug round the jelly till I found the diode then I checked it to make sure it was bad. It was. I'm sure someone that is good with this sort of stuff and has the proper tools could solder in a new diode pretty easy.. What I did was solder a wire to each diode terminal, then I connected the diode to the wires. That way... if it blew out I could replace it more easily. My rectifier was bad and kept blowing the fuse and diode. Hope this helps. I have two MPEMS I made the way so I could used them to TEST. Hope this helps.