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Troubleshooting HappiJac Powered Trailer Jack Model 4150 That Will Not Go Up or Down


I have a 2004 Artic Fox slide in camper made by Northwood. One of my Jacks will not go up or down with the battery or electrical. But I can get it to work if i use the crank or my drill. Do i need new head or gears. My jack is a Happy Jack #4150. It uses the battery remote control. HELP!


Expert Reply:

I totally understand the inconvenience of having to manually crank or needing to use a drill to raise and lower your powered jack when you're used to the convenience of a remote control. Don't worry, I will help you get to the bottom of it. Below are some of the troubleshooting steps I suggest you try if you haven't already done so.

First, go ahead and reset your receiver by simultaneously pressing the "AUX IN" and "AUX OUT" buttons on your remote to see if it simply needed a reset.

It's possible that you are not getting sufficient power at the receiver to operate the jacks so next, charge the camper battery or connect directly into AC power.

If the jacks are still not responding it's likely one or more of your fuses are blown on the receiver board. Replace the blown fuse(s).

If after performing all the above listed troubleshooting steps your jacks are still not working and the motor is not responding then the motor/gear head will need to be replaced with # LC182515. This is a direct replacement for your HappiJac model 4150.

You probably would not be able to operate the jack using the manual crank or drill if the gears inside the shaft were damaged so at least you know that is all in working order.

I've included a snip of the HappiJac Troubleshooting Guide I found online.

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Biily H.

Thank you etrailer for putting the troubleshooting guide online. I was able to repair my happijac by just installing a new fuse. I didn't realize the happijac main board had fuses also. Now I see why I keep coming back to etrailer for my needs.

Etrailer Expert
Reply from Chris R.

Awesome. I'm really glad we could help!


My happijack 4150 will not extend but keeps making the engaged clicking sound as if it is engaged.I have released the lever and the clicking sound goes away and the motor sounds normal but will not extend . Have I retracted it too far disengaging the drive and is this why it will not extend manually and how can I repair it.Is there a simple diagnostic routine I should be using as there does not appear to be any literature explaining this problem?

Etrailer Expert
Reply from Chris R.

If the jack won't even extend manually then there's likely an internal issue with the gear or drive shaft like you mentioned. This isn't something that's easily repairable - your best is likely a whole new jack.

Reply from Jeff

@ChrisR thought as much Thanks

Etrailer Expert
Reply from Chris R.

@Jeff No problem.

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