I picked up a Lx188 that somebody threw out on the curb. I talked to him and he said he did not know if it ran but he kept it inside the garage when he bought the house. Any way I pushed it all the way home and started to work on it and when I put the battery charger on the mower all the lights came on when I turned the key. I think I hear a click from the starter or some where in the engine. I checked the engine and it does rotate freely.
It takes a lot of juice to spin the starter motor. A weak battery can easily power lights. Bertrrr is spot on. If you don’t have a multimeter to check voltage, a quick way to rule out the battery is to take a good battery from your vehicle and connect it to the JD. If the starter engages and turns the engine over, you know for sure that you need a new battery. After sitting so long, you probably will have a stale fuel or dirty carb problem once you solve the starter issue. Come back if you get stumped again. Good luck. That sounds like a great find.