Starts But Stops after 2 Seconds Everytime Now

[RCW]

You have a stop solenoid feed issue.
Is this right?
It cranks starts and as soon as /or within seconds of letting off the key from crank it dies.

Say you replaced the stop relay, is a little odd because it shouldn't have one.

There are two power feeds and a ground that go to the stop solenoid.
#1 feed is the White from the starter, this is the pull in signal.
#2 feed is the Red / Black this is the hold signal.
Black is ground.

The fact that you say when you wiggle the key the lights flicker is pointing to a bad switch or wiring connection.
With a simple test light put it on the red back at the solenoid, if the light flickers or does not stay lit with the key in run, you will need to chase the issue down.

Yellow is crank signal, blue is hold signal.

View attachment 147021

Steve/Jonny and Mike - - -

I'm so glad @North Idaho Wolfman posted this.

@Russell King was heading that direction also.

Key switches are known to go bad. A tractor of that vintage is also prone to some bad connections.

Betting a $7 test light will serve you well.......and I'm not good at electrical stuff at all.

Good luck!