Atwood Tongue Jack not working

roned2 · 04-19-2009, 11:07 AM

We stored our 3124 trailer over the winter. I took out the battery, drove to the storage place, and raised the jack from the car using the car battery power. Today I went to check on the Trailmanor. I have not put the battery back yet. I plugged into the car and tried to raise/lower the jack. Nothing. My signals, brake lights and brake controller work. Have I got a bad jack? Any other suggestions.

**ShrimpBurrito** · 04-19-2009, 11:53 AM

When you say you "plugged into the car", do you mean you plugged the jack into the car's cigarette lighter? If so, check the fuse for that circuit.

Dave

roned2 · 04-19-2009, 12:38 PM

No, I mean we plugged into the 7 pin connector which also controls the tail and brake lights.

**ShrimpBurrito** · 04-19-2009, 01:32 PM

Ah, that makes more sense. I don't have an electric jack, but I presume there is a fuse to the jack on the TM then, so I would check that first.

How is the jack wired to the TM?

You might also follow the wires from the jack to whereever they go out of sight. Look for a loose connection, broken wire (from a mouse?).

Dave

**ShrimpBurrito** · 04-19-2009, 01:39 PM

Thinking more, the positive lead from the tow harness goes straight to the positive battery terminal, so unless that lead is connected to something, the power is going nowhere. In contrast, the tail and brake lights operate off of different pins in the Bargeman connector, so their operation is irrelevant to the TV's power to the TM.

So I bet to get that jack working, you have to reinstall the battery, or at least short the negative and positive battery leads together if that is not possible. You could also just plug the converter into an AC outlet.

Maybe it working last year because the battery terminals was coincidentally shorted when you operated the jack.

That's my guess anyway.

Dave

**Bill** · 04-19-2009, 02:31 PM

NO NO NO! Don't short the positive and negative battery terminals together! That will put a direct short across the tow vehicle battery, and things will get exciting, somewhere, fast!

And on a lighter note, do you have a swing tongue? If so, the problem is undoubtedly the ground between the tongue (where the jack is mounted) and the frame (where the negative side of the power system is connected). As a long-term measure, you should add a short jumper wire across the hinge. As a temporary measure, a jumper cable will do it. As a matter of curiousity, when you put the TM away, were you hitched up, with weight on the hitch ball? And when you tried it recently, was the TM not on the hitch, with the weight supported by the scissors jacks?

If you don't have a swing tongue, Dave's idea of a blown fuse somewhere is a logical next step. You have a 2008 TM, so I think you have an outdoor "porch light" on the street side that you can turn on without opening the TM. Does it work?

Or it could be that a contact in one half of the Bargman or the other got corroded. Since the jack pulls a lot of power, it would show up in that connection, where it might not show up in the connection for the lights.

Bill

roned2 · 04-19-2009, 02:52 PM

Thanks for the suggestions. Just another newbie mistake. I did not realize where the fuse for the jack was. Found it today- the cover had popped open during the winter somehow. The fuse was still there just not connected. My jack now works. Just in time for our big trip across Canada and the US next month.

**ShrimpBurrito** · 04-19-2009, 03:11 PM

Quote:

Originally Posted by Bill

[color=red]NO NO NO! Don't short the positive and negative battery terminals together! That will put a direct short across the tow vehicle battery, and things will get exciting, somewhere, fast![/color

Hmmm...didn't think that through enough obviously. I guess that will happen because even though the TM battery shorts the battery terminals together, it's also a load on the TV alternator/battery. Is that the reasoning here?

Dave

**Bill** · 04-20-2009, 11:14 AM

Dave -

You need to think of it this way. In the car, there is a big red wire that carries 12-volt power from the battery to every electrical device in the car. There is also a big black wire that returns from every device in the car back to the battery.

In the trailer, there is also a big red wire that carries 12-volt power from the battery to every electrical device in the trailer. There is also a big black wire that returns from every device in the trailer back to the battery.

At the Bargman connector, the car's big red power wire is connected to the trailer's big red power wire, and the car's big black return wire is connected to the trailer's big black return wire.

Perhaps the sketch will help. I've shown the car's power system, including the battery, the alternator that charges it, and several electrical devices in the car. I've also shown the trailer's system, including its battery, the converter that charges it, and several devices in the trailer. They come together at the Bargman connector, essentially forming one big system.

Assuming the diagram makes sense, you can see that if you remove the trailer's battery, and short its wires together, you short out the entire big system, including the car's battery.

Did that make any sense?

Bill

04-20-2009, 04:30 PM

This may not be related to the above issue but I found this out the hard way. On my tongue jack, there is a single wire (12+) that goes straight from the battery and it takes (12-) from chassis ground.
For TM's with a swing hitch, the quality of contact relies on the pivot point. Since the entire assembly is painted black (insulated), a little rust on some bare areas and cause trouble especially if you have not used the swing hitch.
I simply wired a ground wire from the main chassis to the swing hitch and everything works. You don't have to drill into the chassis the bolts that hold the propane tank will do.