I have a Nissan 240sx that I just recently started having trouble with. Originally the radiator went bad, but that's a story for another day. I've replaced the radiator and everything went smoothly but just before then, I realized the battery was dead. I mean dead dead, no lights, no clock, no dings to tell me the key is inserted, nothing. Now when I drive it, it lurches if I get over 2500-3500 rpm, as I drive it, the electrics will cut out all at once, again, clock, lights, the engine loses power briefly and then everything comes back. Also, the windshield wiper has a mind of its own.

Now, I drove it all summer with no problems, this only started occurring after it sat for a while after a drift day. The battery never drained when it sat in the past so I don't know why it would be now. Maybe the alternator is bad? But that doesn't explain why the electrics are so goofy while it's being driven.

Last piece of information is that it does not have the original motor. And the swap was very poorly done. But like I said, I drove it all summer without issue. Any ideas before I start planning an engine swap?

Thanks in advance everyone.