The actual problem is the ignition itself, not the lock cylinder. I repaired the one in my '89 years ago so the memory is kind of foggy but... It's a rectangular metal box with a plastic top, the lock cylinder moves a rod which moves electrical contacts in the box. I don't remember if wires were plugged into one end or both. The plastic top is held on by metal tabs, which over time become loose and the electrical contacts also become loose inside. I removed the one in the '89, opened it up, rebuilt it, and reclosed it tight. You should only need to make sure the tabs are holding the cover tight for now, and then find a replacement. The replacement should be revised, as this was a recall and replace item back then.