97 SPX 787 Wiring NIGHTMARE

[riffe723]

Hey all. This is one of my many projects right now. Looking at some wiring for a trashed spx 787. Really looking for a diagram or something. Also wonder if i have all the pieces and all the right pieces. Previous owner says engine runs but lost spark. Engine is already apart and what a shit show. There is no way it ran very good. Cylinders were glued down with RTV Black, what a mess. Anyways any help is appreciated. Also i was thinking that the 97 spx 787 was a DESS post but the post that is in this box of electronics is the old style button.

 

[GGuillot]

Looks like a mess, but you should be able to sort through it and clean it up. The SPX wiring schematics is in the technical data, section 12 of the 1997 Service Manual.

I'm having trouble attaching it, but do a search, I found it out there and downloaded it.

 

[riffe723]

Looks like a mess, but you should be able to sort through it and clean it up. The SPX wiring schematics is in the technical data, section 12 of the 1997 Service Manual.

I'm having trouble attaching it, but do a search, I found it out there and downloaded it.

Thanks. I have the manual here. I'll have a look

 

[mikidymac]

You can't use that switch if it is 1997 electronics as the MPEM is DESS.

 

[riffe723]

I knew that. Previous owner tried to rig it up. Key and Dess post are missing

 

[riffe723]

Someone was saying they could make the old posts work with DESS mpem

 

[riffe723]

Previous owner said trim worked good. Lol maybe 5 years of corrosion ago. Lol

 

[mikidymac]

No, you can't bypass the DESS.

 

[riffe723]

Will a mpem with complete electrical box and two dess keys from a 97 GTX work with my 97 SPX 800?

 

[Matt Braley]

Yes. If your gauges work you'll likely have to swap a couple wires there but they are all color coded.

 

[riffe723]

Awesome. Found plenty of MPEM to replace this one then. I don’t mind spending the money to fix it however I’m going to wait until the motor is back together and see if the current one works or not. Like I said previous owner said it lost spark. And the mpem box was torn apart like you see when I bought it. The rear electrical box is in similar shape. Some people just shouldn’t work on this stuff.