I had a 240 I'm pretty sure that the lift pump runs off of the key switch and the other terminal powers up the circut board that has all of the gauges and safety features. The other I do believe Is for the starter crank. The one i had I had problems with the seatbelt switch and the seat pressure switch and the circut board. The circut board is a problem on these machines. I found out that I wasn't the only one with the problem. Our local deere dealer enlightened me about that. Something is shorted to ground. I would disconnect the plug on the backside of the key and jumper the terminals from the switch till whatever one pops the fuse and follow it from there. So you can get a directon on where to start. If your circut board goes bad ever I just made my own harness with a relay for the boom unlock and wheel unlock solenoid and one for the fuel shut off solenoid. I ran it all through a toggle switch and through the seat pressure switch. That way the circut is interrupted when someone isn't in the seat. The board was rather spendy the re-wire took some time but It was way cheaper than buying another board to have it go bad again. It worked great for the following year that I owned it till it got traded for a bobcat with the smooth running, quiet, great starting kubota diesel in it. Best thing I have ever done.