Tongue Jack... Yet again.

[Belbein]

My electric tongue Jack has packed it in yet again. As always, it's when I'm pressed for time. It's been an internist problem since I bought the trailer new four yeasts ago, and neither warranty work not private necedades have fixed it. I need some help trouble-shooting it.

Symptom : the jack won't raise and lower.

Observations: the jack light goes on, so there's power. The battery is fully charged (and new.). Yesterday when I was hand - cranking it to hitch it up, I touched something and it briefly lowered. But when I tried to do anything more, it died.

Plan : take the plastic cover off, then
--electrical test for power to the connections
--remove and examine the connections
--switch out the switches?
--sacrafice a goat?

[SteveSueMac]

A guess here - if you could get it to move with the hand crank, the gears are ok. If the light works you’ve got power. I’m guessing the switches are fried. I replaced mine in about 10 minutes. Good luck.

[STREMN]

I just did a little PM (Preventive Maintenance) work on mine. My jack is electrically grounded via metal to metal contact with the frame of the trailer. The positive side is via a fused connection into the motor control head.

Simple corrosion can inhibit current passing through the motor. Despite your lights on the jack working (low draw)...your motor is significantly higher and rust can stop that flow.

My PM work consisted of supporting the frame with a floor jack and jack stands. That enabled me to remove the jack from the tongue. I cleaned up any visible rust on the tongue frame and the jack mounting plate. This creates clean electrical contact surfaces for current to flow.

Here's a troubleshooting video that may help: https://www.youtube.com/watch?time_c...&v=FlifxskaIAw

All the best!

Tom - S/OS #025

[GCinSC2]

2 questions.

What brand of jack?

How big is the goat?

Tom's video link does have a quick ground check technique, worth trying.

[Gsmblue]

The switch on my Barker jack failed, apparently this is common. It is easy to replace and I put a spare in my toolbox. Of course the spare hasn’t been needed and I did the replacement 3 or so years ago...

[Belbein]

First of all, the goat will be the biggest one I can catch. Since I'm a vegetarian, I'm not sure what "sacrificing" means in this context, but anyway, first things first: I have to catch the goat!

Second: Don't have a clue what the proper brand name of the jack is: it's weathered off. I call it "that !%*^$# jack." My pet name for it.

Third: I watched the video, and as always, it looks really easy. Except: He says "taking the grounding wire from the battery pole," and there's an arrow that points up the pole suspending the motor for the jack. Does he mean the grounding wire from the battery terminal?

The thing is, from the top of the jack motor, there are two sets of wires that head to the switches. One set is obviously power. The other at the top is identifiably the ground, but that obviously won't run to the foot of the jack to test the ground. Feeding into the motor from the bottom is a single wire. I'm knowledgeable enough with electricity to know there should be a positive, negative and ground, but I'm challenged enough to wonder where the three wires are when there's only ... one wire.

[jimfa440]

It doesn't take a lot of current to operate the light, It does however require a LOT of current to operate the jack. Check your power (red) connection, the ground is supplied through the metal trailer frame. Check the bolts under the jack base. There will be 3 bolts, under each bolt, between the jack base and the trailer frame you should find a star washer at each location. The star washer will "bite" into the metal of the jack base and the trailer frame to ensure a good ground. If the star washers are not there, get some. Been there, done it.

[rucos]

Ive replaced my switch twice since 2015....easy to do.....both times it had corroded .... i now keep the jack head covered with a waterproof cover.....seems to be working but only time will tell !!

[Gsmblue]

Ok, so in the DC 12V world there is only Positive and Negative. The Negative can be referred to as the ground.

The wire on the outside of the jack is probably your positive and should have an inline fuse.

Pictures would help people understand what jack you are using. I am assuming as our trailers are of a similar vintage we have the same unbranded jack, but I could be wrong.

It is definitely worth checking your grounding situation through the bolts as described.

I would put money on it being that darn switch.. It is super easy to replace. Take pictures of how it is wired before removing any wires though!

[Lucilolucky]

Originally Posted by Belbein

My electric tongue Jack has packed it in yet again. As always, it's when I'm pressed for time. It's been an internist problem since I bought the trailer new four yeasts ago, and neither warranty work not private necedades have fixed it. I need some help trouble-shooting it.

Symptom : the jack won't raise and lower.

Observations: the jack light goes on, so there's power. The battery is fully charged (and new.). Yesterday when I was hand - cranking it to hitch it up, I touched something and it briefly lowered. But when I tried to do anything more, it died.

Plan : take the plastic cover off, then
--electrical test for power to the connections
--remove and examine the connections
--switch out the switches?
--sacrafice a goat?

Remove the cover and check the ground wire at the screw. Then make sure your power wires are solidly attached.

[Kyoshi]

I had the same problem. I went thru several fuses. Had the dealer put an inline fuse at the battery and solved that issue

There was also an issue with it stopping and wouldn't lower or raise. Apparently there are limiting switches and I had them changed to allow more range of motion and that issue was resolved.

[Belbein]

I don't understand the bit with the star washers. I understand that they allow a good ground to the raw metal of the trailer frame ... but shouldn't there be a ground wire attached to the washers to achieve a ground? Or is it just kind of the metal in the jack structure acting as a conduit to the raw metal of the frame? This grounding bit is truly something I've never understood about 12v systems.

[Hoagie]

I had a very similar issue on our latest trip. The light on the jack head would come on, but the jack would not operate. With the light coming on I assumed (we all know how assumptions work out with RVs, right?) the fuse was okay. I figured it was either the switch for the motor or the motor itself. Dug out the hand crank, which I had not seen or used in 2 years, and got an immediate lesson in why we all have power tongue tacks.

Continued using the hand crank until we got to a stop where I had the time to disassemble the jack. At that time I found the light wasn't working either. "Bad fuse" I think. Opened up the battery box and "bumped" the positive lead that runs to the jack. Lo and behold, the light came on. "Loose connection" I think. Nope. The terminal on the batter post was tight. took hold of the fuse holder and the light flickered. Pressed the two halves of the fuse holder together (it is the tubular type) and the jack motor started operating again. I was able to use the jack by having the DW hold the two ends of the fuse holder together tightly while operating the jack. Did this until we got home. I found the fuse holder had corrosion on the terminals that led to the issues I experienced.

So even if your connections all look good and the fuse is good, you can still experience issues with your tongue jack due to hidden corrosion inside the fuse holder.

I'm going to replace the fuse holder with a blade-type fuse holder designed and rated for use in a marine environment. These have a tight fitting rubber cover that goes on over the fuse. Hopefully this prevents this issue going forward.

[STREMN]

Originally Posted by Belbein

I don't understand the bit with the star washers. I understand that they allow a good ground to the raw metal of the trailer frame ... but shouldn't there be a ground wire attached to the washers to achieve a ground? Or is it just kind of the metal in the jack structure acting as a conduit to the raw metal of the frame? This grounding bit is truly something I've never understood about 12v systems.

Belbein - Star washers are to break through the paint and rust to allow good metal to metal contact between the trailer frame and the frame of your jack. The trailer frame is the 12v- negative connection (aka ground) to your battery.

Corrosion (rust) between the jack frame and trailer frame can lead to a poor electrical connection between the two parts. It may be Ok to run the light but not enough current flow to run the motor on the jack. The troubleshooting video illustrates a cable coming directly from the negative terminal on the battery to the foot of the jack.

The 12v+ positive is a single wire usually with an inline fuse essentially coming from the positive post of your trailer battery. Hoagie makes a good point about the fuse holder...

In one of your posts you'd said the jack started working and then stopped as it was moving...this is another good indicator of a poor connection. Wiggle, man handle and move some stuff around (power line, fuse holder, jack head) while you're flipping the switch to run the motor. You may just figure out where the problem lies.

My guess is corrosion...YMMV.

All the best!

Tom - S/OS #025

[alphamale49]

I had the same problem. Light worked, fuses OK, battery ok. Wires to switch were loose. Fixed by dealer.

[GeeSag]

Who knows about good and bad switch designs?
And can elaborate if using "Solder Mounds" as switch contacts is a bad design as opposed to blade switches.

My Barker Jack Switch went bad, but I had an indication it was going bad by it started to become intermittent and would work some of the times and other thimes I had to press it a few times to get the motor to run.

So I replaced the switch.

I then dis-assembled the old switch.

The internal slide mechanism is a spring loaded printed wiring type board that slides over the Mounds of Solder.
Since the motor pulls high amps, it seems that relying on a mound of slder has the potential to be a bad design.

It just looks like a cheap switch on the inside.
Seems like a blade switch would have a much higher reliability.

I agree with above post: Buy a couple and keep one in the tool box.

[Belbein]

Originally Posted by STREMN

Wiggle, man

I wiggled and wiggled--fairly even twerked--but other than some catcalls from passing traffic, the body english didn't have any effect.

[Danecoyer]

Do yourself a favor, replace with higher rated jack. I did it in an hour by myself and no
Problem since then.

[Belbein]

Originally Posted by STREMN

The trailer frame is the 12v- negative connection (aka ground) to your battery.

Tom, you're saying something here that I don't understand, but I'm not sure I know what it is. So let me repeat what I think I know, and you can tell me where I'm getting it wrong.



The battery has two principal wires coming off of it, Red (+) and Black (-). Red is power, Black is the return current. These go to the trailer's "house" circuits.



Question 1: But where's the separate ground, as in 110 v. systems?


In any case, there's a third wire coming off the battery, a thin red one. This goes to the jack. It's the only wire to the jack. However, when it comes out of the top of the jack to the switches, it's now several different wires, which appear to be red, black and yellow, going to the switches and what appears to be the gound, as a yellow wire.



But what I don't see is a Black (return) or a ground.



Question 2: So when you say "the trailer frame is the ground" I'm wondering how it fits in the electrical circuit? I understand that you "Ground" the circuit to the trailer, but physically how does that work? How do those poor electrons ever get home if there's not a black/-/return from the motor to the battery?

[STREMN]

Originally Posted by Belbein

Tom, you're saying something here that I don't understand, but I'm not sure I know what it is. So let me repeat what I think I know, and you can tell me where I'm getting it wrong.

The battery has two principal wires coming off of it, Red (+) and Black (-). Red is power, Black is the return current. These go to the trailer's "house" circuits.

Question 1: But where's the separate ground, as in 110 v. systems?

In any case, there's a third wire coming off the battery, a thin red one. This goes to the jack. It's the only wire to the jack. However, when it comes out of the top of the jack to the switches, it's now several different wires, which appear to be red, black and yellow, going to the switches and what appears to be the gound, as a yellow wire.

But what I don't see is a Black (return) or a ground.

Question 2: So when you say "the trailer frame is the ground" I'm wondering how it fits in the electrical circuit? I understand that you "Ground" the circuit to the trailer, but physically how does that work? How do those poor electrons ever get home if there's not a black/-/return from the motor to the battery?

The negative terminal of the battery is connected to the trailer frame...that's why you only see the red positive goto the motor. No other wires involved...