Good to know! If I do find oxidization on the metal connectors, is there a proper method to clean them? Can I just dremel the shit out of them with... like... a wire disc brush?
I did check the ground wire to be sure that was still connected properly right off the block (metal on metal) but I haven't looked very closely at the ground coming out of the headlight/speedo bulb. I'll check on this next.
I've got a spare bulb laying around that I can plug in to verify if the bulb is blown. Would I be correct in thinking that if the headlight bulb burns out, it would prevent the running tail light from working?