Genie Z45/22 No forward movement suspect electrical issue

I have a 1998 Genie Z45/22 serial ending in 008826. It was driving fine then all of a sudden would no longer drive forward however it drives in reverse as expected. Having someone hold the lever I manually actuated the pump and the unit moved forward with full power which indicates the main hydraulics are working and suggests the issue is either electrical or with the flow control or proportional valve control. The wheels will jerk slightly forward when you push the joy stick all the way forward (only in turtle no movement at all in rabbit) otherwise there is no movement. I did a continuity test on all wires from the platform control box to the ground control box including wire 30,31 which I believe are for EDC Forward/Reverse? which seem fine. I manually tested all switches, resistors, fuses, breakers and potentiometers and all checked out normal. I am seeing 24ohms of resistance between wires 30 and 31. I'm not sure if this is normal or if it indicates a fault.
In the process I've replaced the emergency stop switch in the platform and both boom arm limit switches. I also recently performed a tune up, oil, filters, etc. otherwise all other functions are working as expected. I found the manuals and tech tips on genielift.com and they have been some help but don't have full schematics or go into much detail.

Most likely electrical issue. And most likely a wire issue. Though you could ohm the solenoids to rule those out.
Do you have a manual? You can get for free from genie website.

Thank you for the reply I really appreciate the assistance. I was able to find the free manuals on genielift.com and they do show electrical and hydraulic schematics but they don't seem complete. I didn't see where you can specify model year and some of the pictures for the Z45/22 manual don't match my machine so I may be looking in the wrong version of the manual. Long story short I was not able to track down the location of the solenoid and/or flow control valve responsible for forward movement but it's entirely possible the information is there and I'm just missing it. I could ohm out every solenoid, if I find one that deviates from the average of the others that could be the bad one. Or I suppose it could be a stuck spool valve but I'd like to be sure I was pulling apart the right one rather than removing all of them. Thanks again!

I'd check wiring all around the valve body and battery. I just recently found a cut ground on a genie that made it lose drive.

I would suspect the joy stick/card. The older genies use a circuit board and you periodically have to adjust the threshold setting. And then sometimes they just give up the goods and no longer send the corresponding voltage in relation to the joystick. Its been a long time since if been in one of those older units but from memory I think there are three screws to adjust and you have to set them with a digital volt meter. You tune the pots to the specific voltage requirements. Forward, reverse etc. You only get so much adjustment out of each pot. If you can't achieve the desired voltage out of each pot in relation to the joystick position you have to replace the assembly. I would check that first since the older units worked on a supply/demand voltage ratio. If that checks out get back to us and we can move on down the trouble shooting chart.

Great information.