Hi, looking for some help with a Skyjack 3219. It was working fine however after sitting for 6 months I went move it after a full charge and it won't drive or lift. The steering works but will not go forward/backward or lift. The wheel lock pins also do not retract. I tried to lift from the ground control and that did work one time but now also doesn't work. The pump runs and sounds strong however bogs down when I try the ground lift like a valve is not opening. I have checked the stop switches and cleaned up all the battery connections. The batteries are fairly old and it worked fine until is sat the 6 months of no use but as mentioned the pump runs strong. What could cause this?
As with any battery machine the first thing to check is the batteries. 24 volt machine. Connect a meter to the master positive and master negative of the batteries, you should see 24 volt static. Actually, 25.2 volts if the batteries were new as each cell has 2.2 volts, but you should see at least 24 volts. Now work a function, which is load, if the voltage drops to 18 to 20 volts then you're going to have operational problems likely caused by failing batteries. If the voltage holds around 24 when under load there's something else causing your problem.
Thanks for the response, I had a chance to do some tests today. Direct to batteries holds at 24v, when putting on load drops to 21.8. I also connected the tester to the contactor relay solenoid which also shows 24v however when load put on drops to almost nothing. The other interesting thing I noticed is the pump did not bog down at all when running tests from the platform control for both drive and lift however when I try ground control for lift is when it really bogs down and you can see the hoses jump.
Quick update as I was incorrect on the voltage at the solenoid at load. I tested the voltage at the motor with 24v at the motor which drops and holds at 21.8 under load for both drive and lift from platform control, it drops to 10 when using the ground lift rocker switch. As mentioned the pump sounds strong and not bogging down at all with platform control however with ground lift control bogs down and really gets the hoses near the pump moving like something isn't opening up. I would also like to mention the steering works with no issues. When trying to drive the wheel lock pins never retract and when trying to lift the feet that typically lower also do not move. I'm at a loss as it doesn't seem to be the batteries as the cause and not sure what is the cause.
I don't know enough about the Skyjack systems to offer specific advice on them. But on any battery machine voltage is critical. If batteries aren't up to snuff, you can drop voltage enough to still operate the motor but it won't be enough voltage to make the magnetic solenoid valves work. And there's not a specific number where that happens, just depends on the component, but you'll typically see problems with solenoid valves when voltage drops somewhere between 18 to 20 volts. And you mentioned one point where the volts dropped to 10 volt while using the lower lift switch. Only thing I can say about that, four GC2 batteries that are in good/proper condition should never drop to 10V even under load of relief valve popped open which would be max load on the system. At that point, dropping to 10V under relief load, good GC2 batteries would be melting cables from the amperage going through the cables.
And I can't believe I didn't ask this earlier considering I've been working on machines like this for over 35 years...I assume you have the water at the proper level in the batteries, correct?
Thanks, I suspect the batteries as well. Yes I did check the water levels and one was a bit low and added water and also cleaned up all the terminals and retightened them with no change. At his point knowing the batteries are fairly old and the machine sat unused for many years before I used it for a few days before it stopped working I think I will replace them and see if that resolves it.
Those GC2 batteries are not cheap, and yes they're aged. Only way to properly load test them is with an expensive carbon pile load tester, those little hand held resistor testers won't phase those batteries. One thing you can do for a bit of confirmation is test the specific gravity of the electrolyte. Battery hydrometers are not terribly expensive, the ones that have the floating balls, but at least get a decent one, not one of those little pocket size hydrometers. Charge the batteries fully, then test each cell with a hydrometer. If you find one or more cell that float only one or zero balls then that's a problem that will affect all four batteries.
Just to rule out on one thing I questioned is the tilt sensor. It has lights on it when trying movement, is it normal to have a green and red light lite up when trying to move or lift? Seem odd that both light up vs a single green or red to indicate a tilt issue. When testing it was on the level and both a green and red light on it the sensor.
I'm not familiar with how the tilt sensor works and what it affects on a Skyjack, can't help much there.