"He went through the trouble of making the wiring run look pretty, including use of that flexible yellow tubing, but did a bit of a mash up on the connections."

That's actually more common than you would think especially considering the length of the run of the exposed wires. I'm sorta opposite. I'll zip tie wires to other bundles & don't mind having 'over generous' service loops but the actual connections must be soldered & if not shrink wrapped, then taped (BTW, I hate crimp on electrical connectors too).

He probably had replaced the windshield washer nipples with lighted ones. When he decided he didn't like them (or they quit working), he went back to the OEM.