Electric Jacks

[garbonz]

A disturbing factoid that I just learned after a near catastrophic failure of my Happijac's. May be relevant to other electric jack also.

BACKGROUND

I went out last Thursday to my shed which is behind the driveway where I park my camper and truck (2007 Chevy LBZ 2500HD extended cab shortbox and 2005 Bigfoot 1500C8.2) and something looked REALLY weird. The passenger rear happijac has, all on it's own, decided to descend to the limit of it's travel and commit suicide. Fortunately, I did not have the tiedown on at the time and the camper merely lifted up at that corner till the jack ran out of travel and decided to stop.

The bigfoot is so well built and stiff, that even shoved up in the air on one corner, caused no damage at all luckily. The happijac on that side was actually okay except it destroyed the housing with the little reduction gears in it, but still worked on the manual bypass socket so I was able to get the camper back down and in place. I have an extra gear head left over from when I changed one of the motors out some time ago so was able to swap out the motor and other housing and get things back functioning.

THE PROBLEM

In commiserating with the factory about this event, I was interested to hear that the control panel is ALWAYS energized unless the power is off to the camper and this type of malfunction has, if rarely, happened before, attributed to moisture getting into the control board or the remote. My control board has not been exposed to moisture that I know of and seem to be working fine right now.

THE SOLUTION.
The recommended fix is to install a switch in the power circuit to the control board and only turn it on when using the jacks and ALWAYS turn it off when not using the jacks. So I did just that, installing a hefty SPST toggle switch in the 12v wire to the control board; needs to be a hefty switch since the jacks carry quite a bit of current. I recommend this precaution to everyone with electric jack if there is not a manual (not electronic) switch between the battery and the jack control board. The happijac people were very helpful and I will be sending my board back to them when I get a chance.

My 2 cents and forewarned is forarmed.

[Unplanned Tourist]

Good to know. I believe in turning power off when you store anything that is controlled by a circuit board.

[garbonz]

Issue here is that you can't do that without putting a switch in or turning off all the power to the rig. This can happen at any time you are not completely disconnected, which may not be all the time. Scary.