Cs2220 won’t start

Just purchased a cs2220 used at 130 hours. Started fine a few times then started acting up due to lots of corrosion on the + battery terminal. I purchased a new battery and it still wasn’t starting. I rescued the terminals and it fired right up. Ran it for 4 hours parked it and then it won’t even try and crank. Glow plug symbol disappears then when you turn the key there is a click then nothing and glow plug symbol comes back. Ir replaced the terminals completely and still no dice. Batter reads almost 13 volts with no drop when you turn the key. Also get 13 volts at the starter but not sure where the trigger wire terminal is.