Hitachi zx200lc-3 auxiliary hydraulics stopped functioning over the weekend HKX controller?

Serial FF01U1Q203192 here. Everything was working fine on Friday, but this morning the circuit keeps blowing fuses.

The dealership that sold this machine to me always used HKX components and controllers for the auxiliaries. Problem is, the identification sticker isn't on the machine anymore. The dealer said they'd try to track down what was installed, but they were bought out by Papa 2 or 3 years ago, so I'm not holding out much hope on getting that info.

Right now I'm pretty suspicious the HKX controller itself is the problem, but I can't spot anything obviously wrong on the circuit board. Even if I could, I wouldn't know what part number to order anyway.

I've already ruled out shorts in the solenoid coils, checked the auxiliary cut off switch, tested the joystick wiring, and traced the wiring from the fuse panel to the controller. All looks okay.

Does anyone have tips for troubleshooting an HKX electrical system like this?

I should've mentioned the auxiliary was mainly running a hydraulic thumb, which is a two-way setup.

Does the fuse blow immediately or only when you try to use the auxiliary functions? You should contact HKX directly—they should have the kit and machine serial number FF01U1Q203192 registered on their end.

It blows a fuse the moment you turn the key on, or when you plug in the controller with the key already on. I'll give them a call.

They turned out to be really helpful. After a lot of testing this week, we ended up replacing the joystick, the controller and the wiring harness. From what I can tell, the thumb wheel on the joystick failed and took the controller with it. Since the controller is obsolete, I need a new wiring harness too. The whole thing is going to run about $3000.

I'm wondering though—why not just swap in a good old-fashioned pedal pilot valve instead? Does anyone know where I could find one? I'm hoping to get one that'll fit the hole in the floorboard where the foot rest sits and can be locked.

I'm thinking I could pull the auxiliary pedal out of my zx35 (serial# FF01MBQ235797) and put it in the zx200lc-3. My dealer hasn't been able to track down that part though.

Can you post a photo of the pedal slot in your floor? I've run into comparable problems with toggle switches going bad on my thumb control setup. I ended up putting in a Kawasaki foot pedal plumbed into the circuit halfway through a job just to finish, and it stayed on as a permanent backup. I'd take joystick control over it any day of the week though—it's twice as productive.

I didn't grab any photos before I left. Where'd you end up getting your pedal from?

Check the ZX200LC-3 parts diagram for the pilot valve, pedal and linkage. A ZX35 valve and pedal might be a cheaper alternative.

Thanks for the replies. I apologize for leaving this hanging. I ended up replacing all the problematic electronics with a treadle valve. It cost less than a third of what the electrical stuff would have, and it's rock solid. My only issue is I could only track down a left-hand pedal. I would've preferred the right foot so operators wouldn't use it as a handhold when climbing into the cab.