Technical Why won't my park lights work?

So, how did you fix the bad connection between the bulb housing and the bulb socket?

A lot of "older" mechanics would put die-electric grease into the bulb socket before they inserted the bulb, it doesn't take much, just enough to "fill" the space between the bulb and the socket.

Also, if you used the tail light power to power the parking lights, the parking light would light up every time the tail lights would. Be sure you remove the parking light power wires and seal them so they can't ground. If you replace the parking light power with the tail light power, the parking light position on your headlight switch may have no function, and you may only get parking lights when the headlights are on.