Replaced the alternator on my 330crt scissors lift. 3 cylinder Kubota engine,dual fuel. Gas/ propane No start after that from top or bottom controls. Can reinstall old alternator and it will start right up but doesn't charge. There are 3 wires on the alternator. 1 big main wire and 2 small ones in a T shaped plug. Wiring diagram says 1 wire is ignition and the other is lamp. Old alternator had a cracked case so not rebuildable. Alternator shop took it apart and found worn away tab that attaches to the voltage regulator. I'm afraid when they replace the regulator I'm still going to have the same results. New one was tested and checks out fine.
Was the replacement an identical unit, or an aftermarket that would fit? Lots of these setups that get the engine speed signal from the alternator.
It was aftermarket that was a replacement for my original part #.
Problem is, the aftermarket will physically fit and charge the battery, but if it's internally different (like number of poles) it won't get the correct frequency signal to know engine speed. JLG used to have all their manuals free online, don't know if they still do. don't remember off and if you can read the output Hz with a standard meter, or which lugs you'd check.
I'm just winging it here because I'm not familiar with that machine, but possible you're missing a "tach signal" from the new alternator. On many aerial machines, both JLG and Genie, the machine computer wants to see a tach signal that indicates the engine is running, common to get that signal from the alternator. Old alternator it runs, new alternator it doesn't. Sounds like missing tach signal. Just a guess.
I purchased a used alternator on eBay. Original Kubota with all matching numbers not just the model number. Starts up like it should. So apparently something in the alternator makes the battery light come on when the key is on and the aftermarket one wasn't doing that. Thanks everyone for your replies.