Visit our Popular Forums

Norm excella · 07-08-2017, 03:09 PM

Whenever unplugged from shore and no battery....complete power by tv, why does electric jack stop working when not grounded to tv ball?

TG Twinkie · 07-08-2017, 03:35 PM

It appears the ground/common connection is missing.
Check the connection at the UCord and trailer frame.

jdalrymple · 07-08-2017, 03:36 PM

The umbilical from the tow vehicle is not supplying a sutible ground wire.

Regards,

JD

uncle_bob · 07-08-2017, 04:10 PM

Hi

Multiple issues or one common one?

1)Hitch "ground" makes things work
2) Jack does not work on battery / shore power

A multimeter is your friend in these cases. It could be any of several wiring issues. Check each of the possible ground issues out. Start with the trailer off the ball, but plugged into the TV. Is there 12V between the trailer frame and the TV frame with the marker lights on? Do the marker lights even light up with the two unhitched? (= it's not just the jack) If everything *but* the jack works either way, do you have 12V between the jack frame and the trailer frame? (weird if true ..)

Yes, it takes some digging.

Bob

Norm excella · 07-08-2017, 05:54 PM

Hitch grounding does make it work.
Jack works fine on shore power and battery just problem with tv

MIsteve · 07-08-2017, 06:46 PM

I have a1984 38' air stream. I just want to make it into an art studio, but I would like to utilize any existing equipment. I just need someone familiar with older airstreams to walk me through the systems. I'll happily compensate either monetarily or in adult beverages. I'm on Merritt Island Fl.. Any help would be appreciated.

HiJoeSilver · 07-08-2017, 07:31 PM

Quote:

Originally Posted by Norm excella

Whenever unplugged from shore and no battery....complete power by tv, why does electric jack stop working when not grounded to tv ball?

If your battery is disconnected you're probably losing the negative return from your trailer electrical system to the tow harness. I'm not sure how they connected the negative from the 7 pin to the trailer electrical. Since the jack uses the frame as it's negative connection there isn't a current path back to the TV unless the TV and trailer have metal to metal contact, which you are getting through the ball to coupler.

uncle_bob · 07-08-2017, 07:33 PM

Quote:

Originally Posted by Norm excella

Hitch grounding does make it work.
Jack works fine on shore power and battery just problem with tv

Hi

Ok, on a normal setup, the jack goes straight to the battery. Unless you have a strange setup, the TV is not involved at all. There are an almost infinite number of ways AS does disconnect switches. If you are in the "disconnect" switch position, normally the TV does not power the jack, the jack simply does not work. There are alternate setups where the jack is always hooked to the battery no matter what the setting on the switch. If you have a version where the jack disconnects from the battery and connects to the tow, that adds a new one to the list.

The jack motor pulls a lot of current. It's quite possible that your 7 pin wiring simply isn't up to the task. Grounding things might be just enough to cut down the drop. Normally a ground issue that stops one part of the trailer will stop all of them. You loose marker lights, turn signals and all the rest. Based on your description this isn't happening with the trailer unhitched. If it is happening, then you simply are missing the ground on some part of the connection to the 7 pin.

Lots of fun.

Bob

1973Argosy · 07-08-2017, 08:53 PM

Ditto on not pulling a suitable ground through the umbilical. The jack is grounded to the trailer frame. If you have a battery in or are hooked to shore power your trailer frame has direct ground. When you jack off the ball you are losing ground to the trailer with no power on the trailer. A simple solution would be to ground between the truck and trailer with a jumper cable.