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Curtis B.
Curtis B., Technician
Category: Industrial Equipment
Satisfied Customers: 594
Experience:  Technican turned service manager on multiple lines of equipment used in industry.
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I have a Marklift 19 JR scissor lift (early 1980s) and it had

Customer Question

I have a Marklift 19 JR scissor lift (early 1980s) and it had been working fine.
A few days ago, my employee was working on the lift and moved forward in the down position to a stop. When he tried to raise the lift nothing would work, including moving forward or reverse or, turning right or left or, going up or down. I assumed it was electrical and have tried to diagnose the problem with my dc volt meter. I can't find the problem with a rudimentary testing of the electrical runs.
Submitted: 1 year ago.
Category: Industrial Equipment
Expert:  Curtis B. replied 1 year ago.
24 volt unit, with 4-6 volt batteries. The control has to close the main solenoid, which turns on the pump motor. Does the solenoid turn on the pump motor? Do you have 24 volts to the pump motor when a function is selected? Does the battery charger come on when plugged in?
Customer: replied 1 year ago.
I have 4-6 volt batteries but the manual says the lift has a 12 volt system. My meter tests out to 12.8 volts. The solenoid does not turn on the motor. I jumped the solenoid and the motor operates but does not lift the cage or go forward or turn when it is being jumped and that function is selected. The battery charger comes when plugged in.
Expert:  Curtis B. replied 1 year ago.
So if the solenoid is not closing, is it getting voltage from the function? Two things have to happen when a function is selected, the pump motor has to come on, but also the function valve in the control block has to open the ports to the function. If no voltage to the solenoid, to close it, I suspect you have a control cable problem.