The engine compartment light, like some of the tail lights, didn't light up. Turned out to be for the same reason, the center wire connection tab where it was riveted to the bulb support brass strip was not making proper electrical contact. Same fix, take the socket assembly off and solder the tab to the support. (Wire was off one side of the switch, checked the switch first for continuity, worked just fine). I drilled a small hole through the rivet, knowing I was going to use a small sheet metal screw to put it back in place, then a larger bit to spin out the rivet and remove the assembly. After soldering decided to redo the insulated portion, it looked pretty doggy. Drilled it out. Took a while to figure what would be fairly permanent, ended with something you don't have, a pin plug socket, such as used on early meters and earphones, it was all nylon with a metal nut to hold it on. Ground down the face to about the same dimension as the original insulator, countersunk the head slightly with a drill bit about the same size as mid point on the bulb, screwed it into place, took a soldering lug of a slightly smaller inside dimension and let the top of the bulb hold it in place under tension, reconnected the wire, should be a lifetime fix. If you should decide to do this I think nylon bolts or screws from the hardware store could have the heads ground flat and countersunk slightly to emulate what I did with the pin jack (the hole in the strip is pretty good size). If you're not of the see-if-you-can-fix-it-before-you-throw-it-out persuasion, this would be of no interest to you.