I have a 1992 Seville. It’s a project car I’ve been fixing up the last couple of years. It’s ran fine until recently. I replaced the alternator and battery but it still hesitates to start and sometimes doesn’t start at all. The engine turns over when you turn the key but sometimes will have to try 3-4 times to get it to start. Today for the first time I turned the key and got nothing. Turned it off and back on and it hesitated but started. I also have an issue with the defrost draining my battery if the car is at idle. Heat doesn’t work but defrost does. The heat stopped working when the A/c compressor went this past August. Idk if those things are related or not but I’m at a loss. When I turn on the defrost it makes a knocking sound for a few seconds then stops. Any advice on which direction to go with this is greatly appreciated.