Legacy K4 losing command signal

Sounds like you have the handrail antenna disconnected, that's usually the issue when you lose command after taking the shell off.  When you lift the boiler, it loses contact with the frame and starts to act as an antenna.

The other possibility is that you have the handrails shorted to the boiler, check with a meter to see if you have any continuity from the handrails to the shell, they should be insulated.

Thanks, Johh.  It's strange.  If I lift the boiler, with all connections intact to the frame/boards, it is perfect.  The moment it makes contact, it won't recognize the signal anymore.  To accept commands again, I just lift the boiler up a 1/4" - 1/2" and it's fine again.  

I will check what you suggested.  

 I've had mine apart,I can't remember where the antenna connects to the hand rails, either under the smokebox or under the firebox area of the shell.  If they connect to the front maybe a wire is getting pinched or you pulled one off.

I recall there were several wires going to the front for the marker lights headlights as well it was somewhat "busy" around the smoke unit.

I've taken it apart a few times, Rick, and always managed to get it back together.  Something is off.  There is so much stuffed into the boiler front area that it is hard to get a good fit, I think.

What you describe matches the handrail shorted to the boiler, though if the antenna is disconnected it will be a similar reaction.

Thanks for the update! The best fixes are the easy ones!

Cheap fix.