Good afternoon,

After reading through several posts in the past regarding this problem, I wanted to share my experiences this morning. Hopefully it's helpful.

After taking the tractor out of the shed this morning read for a brisk morning of snowblowing, the PTO on the tractor wouldn't engage. The temperature was about -12F at the time. Pulling up on the yellow knob did nothing. The tractor would start and would drive with no problems, although the fluids were still really thick and steering and snowblower hydraulics were very sluggish. The PTO light on the dash would not come on, and the red LED on the circuit board found beneath the console inside the right access panel would not come on when the knob was pulled.

I spent hours on the 'Net looking for clues as to the problem. It came down to either the seat interlock switch, the brake interlock switch, or something had gone terribly wrong with the clutch. The symptoms were electrical since there were no indicator lights doing what they were supposed to do, and the PTO won't go if either the seat interlock switch or the brake interlock switch are faulty. I tested the seat interlock switch first and it was working properly. It's also the easiest to test.

At this point, I figured it had to be the brake interlock switch. The brake interlock does two things. If the brakes are on, the PTO turns off. If the brakes are off, the tractor's starter won't engage. I climbed on the tractor, took the parking brake off, and attempted to start the tractor. It started right up! So, now we've got the culprit. The brake interlock switch is either faulty or stuck.

On another forum, a poster noted that on really cold days that his brake interlock switch would freeze. So I went on a search. After what seems like hours of searching, I found the brake interlock switch on the left side of the tractor outside of the frame rail, opposite of the brake pedal. It's a little grey assembly with a plunger that's facing downward and an electrical connector on top. There's an actuator shaft that's welded to the brake pedal, and runs across the tractor about as far back as the steering column is. There's a small lever bolted to it that presses the button in when the brake pedal is pressed.

I tested the brake interlock switch, and it was indeed sticking. I had some Radio Shack contact/tuner cleaner with a lubricant built into it that helped to loosen things up and get the switch operating properly again. I don't know whether or not WD-40 or a similar lubricant would do the same thing or if it's harmful to the switch plastic or internals.

Now my PTO and snowblower are working properly. I wanted to share that with any of you who may be having problems with their JD425 PTO in the winter time.

Thanks and best regards,

Chris