Hi, I am Tech Spanky sorry for long delay and will be assisting you today. I am a Master Technician with over 30+ years experience that's dedicated to giving you the best Answer possible.
There are two lift limit switches,,,,the first one trips at 10ft and should cut out high speed drive,,,,the second one should cut out drive when you raise lift all the way up,,check the arm on upper lift limit switch,,associated wiring,,and switch itself.
They look like this click here
A lot of times the arms get bent or loose so they don't get tripped either going up or down,,, so once you hit first limit it's cutting out drive instead of just high gear.
If you are new to the site, this is briefly how it works:
1. We may need some back and forth to exchange information (if needed) and there is no extra cost for replying.
2. I will give you the best possible Answer for your problem without the ability of actually being present with you.
The better you describe the problem, the quicker I can help ;-)
3. Remember to leave a Positive Rating after we're finished. it doesn't cost anything additional to rate kindly;-)
I am only compensated for my time and expertise if you rate kindly.
Questions or problems let me know I'm happy to assist.