Lx188 PTO problem

My guess would be the brake pedal safety switch is stuck so that the tractor thinks the brake is engaged all of the time, even when it is not. All other functions of the tractor, starting the engine, getting off the seat with the engine running, etc, can be done with the brake pedal safety switch stuck in the "brake pedal depressed" position, but engaging the PTO is not allowed.

The seat safety switch will not allow the PTO to engage if it does not sense the operators weight on the seat, but if it was stuck in that position then you would not be able to start the engine either.

Brake switch and seat switch appear to be working properly.

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Can you start the tractor without pressing the brake pedal down?

And you say that turning the PTO switch on actually causes the engine to die? Sounds like either a short somewhere or maybe some electronic safety circuit is malfunctioning.

Another question - Have you had the tractor for a while and it was working fine and just recently started doing this, or has it done it since you got it? If it has done it since you got it then maybe a previous owner wired something up incorrectly.

I would get the service manual and the electrical schematic and start with a full electrical system check. Make sure that everything is connected as it should be and then follow the troubleshooting procedures in the manual.

I agree, the only thing the belt would do is put lateral stress on the pulley, clutch and shaft, so probably a loose wire inside the clutch that only shorts when the pulley has the force of the belt pulling on it.

But I would think that a dead short would blow a fuse. So maybe not a direct short, but a short from somewhere partially through the electromagnet coil in the clutch, so it doesn't draw enough current to blow a fuse, but it draws enough that the charging circuit can't provide enough electricity to run the ignition circuit.