John Deer XL188 wouldnt crank

I got new fuel pump, replaced all filters, and it cranked and I mowed the front yard then it quit and I got new battery and it cranked and when I sat down on seat it quit and I cant get it to crank. What now?

Look for loose wires, bad connections, poor grounds. The next step would be a wiring diagram.

First off, I think you're talking about an LX188. Does it have the 48" deck? That's what they came with from the factory. Second, are you detting the park brake? You have to push that Big pedal and lift the Right red handle, below and right of the steering wheel. Last there is a switch under the seat. if the switch is bad it might work backwards. It is designed to shut the motor off, if you raise up off the seat, when the mower is running and the park brake is off. This can be bypassed by unplugging it, and putting a jumper wire in the plug itself.. One last caution, make sure you press down on that large pedal whenever you are going to use the park brake. failure to do so and you can break it.

My LX188 had the same issue one time and it was the key switch with the board that was bad.