1997 GTX, tries to start when connecting battery

[mmanning]

Thanks to the members, great advice here. I've been lurking for too long, it's nice to be a member. So, I've got a 97 GTX. When I connect the battery it immediately tries to start. My battery was dead and I jumped it using my boat battery. The boat battery was in the driveway and not connected to anything so the voltage should be the same and I cant see how it could have caused the issue. I've heard of damaging the MPEM from high amperage charging systems. When the problem started I checked the wiring at the solenoid and it was corroded at the main plug to the box. Some wires had minor melt and others were corroded inside the plug. I replaced the plug with another 4 pin plug and made sure it was wired the same. There is one wire connected using the black on the 4 pin that is just connected to the ground post on the battery. You can see it in my pic tied to the rest of the grounds inside the box. Is this proper? where does it go from the factory? It was setup this way when I got it. When the problem is solved I'll order a new factory plug and put it back to factory so its waterproof. For now its driveway troubleshooting..

When I connect the battery the solenoid connects and never releases until I disconnect the battery. I believe the engine would start but the starter would keep spinning.
Doesn't matter if the key is connected or not, turns over either way
Start button is not sticking (verified with volt meter, no continuity until pressed)
Yellow power wire to the plug on the solenoid is constantly at 12v and causing the solenoid to attempt to start. For now I disconnected the starter wire for trouble shooting

Any ideas? If I blew the MPEM I'm not sure why. Either way I'd like to verify before throwing parts at it.
I bought the machine used and I attached a pic of the MPEM. Not sure if it's original.
I also included a pic of the started electrical box.

 

[GGuillot]

Seloniod is likely fine, need to figure out why the yel/red wire running to it is staying hot.

Looks like an aftermarket MPEM, which can have some weird issues, that MPEM has something going on to cause that yel/red line staying hot. The start/stop switch routes directly through the MPEM. Verify on the downloaded schmatic for the 97' GTX, something may be crossed up. But,
if you've done everything you can and everything is connected properly, I'd try a good used OEM MPEM.

 

[mmanning]

Seloniod is likely fine, need to figure out why the yel/red wire running to it is staying hot.

Looks like an aftermarket MPEM, which can have some weird issues, that MPEM has something going on to cause that yel/red line staying hot. The start/stop switch routes directly through the MPEM. Verify on the downloaded schmatic for the 97' GTX, something may be crossed up. But,
if you've done everything you can and everything is connected properly, I'd try a good used OEM MPEM.

 

[mmanning]

Thanks for taking the time. I appreciate the advice