Hi,
I've got myself a handful here. I just bought a 1968 hi-lo and I am trying to figure out the wiring of everything... please excuse my ignorance, this is all new to me.

Looks like there is a wire coming off of the hydraulic lift, runs under the camper to the front tongue area and then is clipped off and taped. I am wondering if you all might know what this cable is supposed to go to. Is there a ground for these? The hydraulics work fine... just seems strange there is a wire running off and it isn't connected to anything. Currently it is connected to the battery and has the hydraulic fluid line running into it. Do I need to connect this other wire to something?

Thanks!
Kadin

That's a very old trailer you've go there. Pictures of what you're talking about might help. Since the hydraulic lift does not supply electrical power, and, according to you the lift system works, I have no idea what the wire is for.

- Jack

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Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter, Fan-Tastic Fan, LiFePO4 battery 12V DC Electrical System, SoftStartRV mounted on A/C
2024 F150 Platinum FX4 3.5L PowerBoost SCrew

Thanks for helping out Jack.

Sorry the photo is flopped on its side... I don't know why.. it isn't flipped in the file I have. Anyways, The white wire is the one I am talking about. It is connected to the hydraulic system in between where the positive (black) cable is attaching... the it just runs out the floor and then not connected to anything.

Attached Images

IMG_0686.JPG (550.1 KB, 8 views)

Kadin:

Doesn't look anything like my Hi-Lo hydraulic set up!!

Are you confident that the wire, or wires (inside the white insulation cover) are actually making contact in there? It's an awful small wire to be carrying a load off that lug.

What's the function of what looks like a brass lever with 2 holes in it? Is it a manual release valve? Could the white wire have been attached to that lever and simply used to release the valve in order to drop the top? Just grasping at straws here......

I'd do the following:

Determine if the white wire has 1 or 2 wires inside? Only 1 makes any sense if it's connected to the ground lug, and is it actually "electrically" connected?

Get out the test meter (pull back the tape on the loose end) and determine if the wire (or one of the wires, if 2 inside) is energized when the lift system is energized.

Or, energize the white wire and see what happens.

Or, forget it and count yourself lucky to have a '68 with a functioning lift system!!

Haha, I certainly do count myself lucky. I sure hope it lasts for awhile!

The brass lever with the holes is what you push to make the whole top go up and down. I believe you push it to the right to make the top go down and push it to the left to make it go up.

The white wire is 100% connected to lug. I really don't get it. I think I'm going to remove it as it seems dangerous... maybe i'll figure out why someone put it there eventually... or maybe not.

One idea would be that it's the remains of a 12V charge from a tow vehicle. Does the main cable from the pump go straight to the battery from there? It could have been an easy way to tie into the battery using a connecting lug already in place.

Nice find on a working '68 though.

__________________
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2000 24' Classic, "We have the technology, we must rebuild it"

Also in the garage, some stuff to pull it:
1999 3/4 ton 'Burb
1993 Roadmaster wagon (well, it probably won't pull it)

Kadin, on modern trailers, white wires are ground wires, and my initial thought was that the white one on your lift system is also a ground wire. But, read on.

What it looks like you have there is a manually operated "solenoid-like" switch that transfers power from the battery to the lift motor if you want to raise the top. In the later trailers, an actual electrically actuated solenoid does that when triggered by pushing the lift switch.

I'm guessing the circuit supplied by the heavy black wire is completed when you push the switch one way. And, it appears the feed to the motor is through the heavy Red wire? Is the red wire also connected to that switch? It should be, if I'm seeing things right.

Now, since it lowers using the same switch, if pushed the other way, there must still be a positive feed from it to the bypass valve. It could use the same heavy black wire as the supply, but then would need only a small amount of current to open that valve. If you don't see any other smallish wire, the bypass valve may be purely manually operated by the "handle" you move, and it may not need electrical power.

I like piperjim's idea of probing the free end of the white wire with a voltmeter. Put the negative probe on the negative post of the battery and attach the positive probe to the end of the white wire.

Now, if you get a 12V reading without moving the switch or if it reads at either side, then it's a feed for some other thing that is no longer there - perhaps a light that has been removed? If so, I'd cap the end with a wire nut so it can't short out against the frame.

If there's no reading, then it's probably just an additional grounding wire which doesn't seem to be needed for anything, since all systems work. You could remove it in that case. You could also confirm it's a ground wire by using the Continuity function of the multimeter. With the battery disconnected, touch one probe to the end of the white wire and the other to the metal frame of the switch. If the meter beeps, it's a ground.

- Jack

Kadin; If the white wire is connected to the lug with the large black cable then it is hot all the time. If its connected to the lug with the red cable then it is hot only when raising the top. You seem to indicate it might be connected to the bracket between the two lugs which could indicate it is a ground wire. If it is hot all the time and goes to the tongue it might have been for a power tongue jack. You have not said which lug (Black or red} the white wire is connected to. As r67 said on that old of a trailer it might have been the charge line from the tow vehicle if it is connected to the black lug. As for the lever my guess is that when you move it to raise the top it manually closes the contacts to power the pump motor and when the other way it manually opens the bypass valve to lower the top. The fact that the wire is white does not make it a ground as many owners when modifying a trailer will use whatever color wire they have on hand. You have not said what kind of electrical connecter you have that connects to your tow vehicle, 7 pin round, 3 or 4 pin flat, or 4 or5 pin round. Knowing this might help in what the white wire might have been for. It won't hurt to just remove the wire as you can always add it back if needed for whatever.

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Jim L & Faye
2805C
2003 Silvarado diesel crew cab
2017 Silvarado, crew cab 1500 6.2L gas w/ 8 speed tranny
central VA