Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. Today he discusses electric tongue jacks.
Electric tongue jacks
My electric tongue jack won’t operate under load conditions. This is a Husky Brute Jack. It works retracting all the time, but only intermittently extending under load. I have checked that the batteries are good, lifted the jack, scraped the metal frame to ensure good contact as well as ground wires bolted to frame. —Jim
If the electric tongue jack retracts fine but is intermittent under load the first thing I would check is the battery. This is a common issue with lead acid batteries as they can get sulfated and seem to have a full charge, but drop dramatically under load. I would put a battery charger on the battery that is powering this jack and see if it still has issues.
According to their technical support, this jack has a ball screw design that reduces friction and amp draw. It is greased at the factory and not designed to be opened after leaving the factory. The rep recommended lubricating the leg going into the ball screw housing with a lithium spray or even “Vasoline”. I would suggest the lithium spray as it will not collect as much dirt and grit that could get up into the ball screw housing.
Check ground wire connection
Another item to check is the ground wire connection to the frame, as this can get rusty or loose and cause a poor connection. When it is not working, maybe even wiggle that slightly. Then check all wiring going to the controller to ensure there are no kinks, scrapes or bare wires that could create what is called an open connection.
If all that is good, then it’s most likely the motor getting weak. Document all conditions you can find when it does not work. What is the ambient temperature? Is it wet outside from either rain or dew? Does it happen at the time of disconnect or connecting? Any factors that might help isolate a condition would be beneficial.
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