So I just got a 1993 del sol running after it’s been sitting for 2 years which involved an engine swap (old one was hydrolocked). Something I’ve noticed when driving is that the speedometer works fine unless I use the light or wipers? I’m assuming it’s a voltage problem but the battery is fine and I had the alternator tested it’s within spec. It’s a manual transmission and as far as I know that’s the only electrical hiccup.