I'm looking for an inverter (12 volt DC to 110 volt AC) for my 1989 Coupe DeVille Opera lighting. There is one on eBay for $59, but not tested. (offers refund if DOA)

Can I replace the GM 20213140 inverter with a compatible one?

 

What I did on my Fleet when the lights quit is find a different year when the lights were chrome and not plastic. They have the 12v bulbs and then you can have something you can change when they burn out. The lites you have still have a 12v wire going to them so the change is very easy, you just have to find the ones with the same footprint that match yours. You could send your inverter away to get remanned if that's the way you want to go.