Well at least you know where to go looking.
BCS the connectors just need to be pushed on farther. (Seems highly unlikely they could work their own way loose. Maybe they got installed that way by accident?)
The most hopeful likely scenario I can think of is one of the wires chafing against a pickup screw. Replacing that would be easy as pie. (I think I even wound up with a spare when I did my install last week.)
If the prongs on the pickup coil or the wiring inside are compromised, you might have to replace the whole coil. (Still easy, but maybe not so cheap.)
I liked using those solder-less connections, but it did seem a little awkward, trying to cram it all into the rout. I trimmed my mounting foam to put less pressure on everything.
HTH - good luck.