Hi,

For me I like BB’s response but staring at manuals can only help find locations of components or where grounds are for them.

With so many things at once so it appears to be a bad ground on a controller box or even power to it.

Look for something like that in a good manual and use your past instincts with eyeballs from there.

When you can work on identifying dirty conditions, it’s those, that will be leading you think it’s poor maintenance and help develop a plan of action.

Phil