Wiring help!

Team707 · 07-05-2022, 04:40 PM

Hi all,

I had to rip the cladding and panelling off and replace the whole frame on the front of my toy hauler on the weekend. It was not fun. Pics and things to come.

In the meantime, I'm putting it all back together and I have a mystery cable!! I thought it was for the negative terminal on the battery so I paid it no mind, but now I think I was wrong, because it is far too small for that. I did have a circuit breaker ( like this one https://www.ebay.ca/itm/234069266715) on the inside panel but I am sure only the two main red cables connected to that.

The black cable goes to a large junction box under the front of the trailer, but from there I have no clue, and I can't find a wiring diagram. Does anyone have any tips?

bsmith0404 · 07-05-2022, 05:53 PM

I think the pics are going to be a must on this one.

Team707 · 07-05-2022, 05:59 PM

There we go, this black wire goes into this junction box.

Team707 · 07-06-2022, 04:56 AM

More context - I have two red cables that went up to the circuit breaker that was mounted on the inside wall of the trailer, I BELIEVE this black cable was also on that circuit breaker block. It is the right length to reach there, and it also has the right size ring on the end, but I really can't be sure at all. I'm going to put it there for now and hopefully not fry anything!

**chuckster57** · 07-06-2022, 05:19 AM

If you have a meter, I would test for continuity to ground first.

Team707 · 07-06-2022, 05:24 AM

Quote:

Originally Posted by chuckster57

If you have a meter, I would test for continuity to ground first.

Good point. I am one of those people who have knowledge to be dangerous and not enough knowledge to actually know anything.

My plan for today was to get a test light (because I've confirmed it's on the 12v system), and ground the test light, then see if power is coming out of this wire.

Then, failing that, put the ground end of the tester on this, and the other end on the battery. My theory is if it lights up when connected to ground, it's a power wire, if it lights up when connect to the positive, it's a ground wire.... but this might be stupid... hence asking the interwebs.

Bustinbeards · 07-06-2022, 05:32 AM

Is it part of the solar plug for a solar suitcase? Looks like what I have on our tt for that purpose.

bsmith0404 · 07-06-2022, 05:57 AM

Quote:

Originally Posted by Team707

Good point. I am one of those people who have knowledge to be dangerous and not enough knowledge to actually know anything.

My plan for today was to get a test light (because I've confirmed it's on the 12v system), and ground the test light, then see if power is coming out of this wire.

Then, failing that, put the ground end of the tester on this, and the other end on the battery. My theory is if it lights up when connected to ground, it's a power wire, if it lights up when connect to the positive, it's a ground wire.... but this might be stupid... hence asking the interwebs.

In theory that would work, but a meter will tell you more. Why pay $15-20 for a good test light when you can pay $20 for a decent meter?

Team707 · 07-06-2022, 05:59 AM

Quote:

Originally Posted by bsmith0404

In theory that would work, but a meter will tell you more. Why pay $15-20 for a good test light when you can pay $20 for a decent meter?

I have both, a multimeter and a test light. I was just trying to do simple tests to match my simple brain. How would you test it?

bsmith0404 · 07-06-2022, 06:27 AM

Put the meter on the resistance/ohms setting and check if it shorts to ground. If it doesn’t, switch to 200 VAC setting and see if you have 120v. If not, switch to 20 VDC and see if you have 12v. The 120v obviously only works if you’re plugged in, which I could assume you’re not, but I never like to assume. BTW, that type of wire is typically on the 12v circuit, but when dealing with electricity, I like to verify, especially if someone else may have had their hands in there before me. That’s why I’d test the 120v side as well.

If you think you know where it goes, you can also check for continuity between the two points on the ohm setting. If the meter leads are too short, get a wire that you can connect to the other end to reach the meter.

**flybouy** · 07-06-2022, 06:29 AM

Just looking at the first picture I'd suspect it went to the battery. If the other end of that cable goes into that 4"x4" J box then remove the cover and find out what it's connected to. You need to trace it out. Just "guessing" could relate in a lot of damage.

Your "testing plan" with a test light is completly flawed. If that cable is supposed to be connected to the battery then it will show nothing. If that wire is supposed to be a positive or negative wire it likely won't have any indications unless a switch is operated because you won't have a completed circuit. You need to find out where the wire goes or get someone to help. In the future, your cell phone camera is your freind. A peice of painters tape wrapped around the wire like a flag marked with location can be invaluable in a picture.

wiredgeorge · 07-06-2022, 06:33 AM

Fella owns a Tailgator older toy hauler and hasn't mentioned what year but probably pre-solar wired. A signature with year, make and model of the camper and same for the tow vehicle would help give context to answers to his question. Under UserCP and then save.

**JRTJH** · 07-06-2022, 07:15 AM

Quote:

Originally Posted by wiredgeorge

Fella owns a Tailgator older toy hauler and hasn't mentioned what year but probably pre-solar wired. A signature with year, make and model of the camper and same for the tow vehicle would help give context to answers to his question. Under UserCP and then save.

^^^ This, plus, prior to about 2016/2017, trailer wiring "color coding" used standard house color codes. In other words, black was HOT and white was NEG/NEUTRAL. Older trailers, like the OP's 2001, probably have "black POS cables and white NEG cables".

Of course, a previous owner could have/might have changed all of that with "owner upgrades"...

I'd remove trailer power, dig into that junction box and see where the "cable in question" is physically connected. Knowing that may provide the answer, or at least a head start on where the cable goes.

Gkri · 07-06-2022, 07:55 AM

Quote:

Originally Posted by Team707

There we go, this black wire goes into this junction box.

That junction box looks like a standard, galvanized interior house type with zero protection from water and it appears to be located on the exterior frame. I would replace that with a weatherproof (NEMA 4) rated box with water-proof connectors.

**JRTJH** · 07-06-2022, 08:35 AM

Quote:

Originally Posted by Gkri

That junction box looks like a standard, galvanized interior house type with zero protection from water and it appears to be located on the exterior frame. I would replace that with a weatherproof (NEMA 4) rated box with water-proof connectors.

Nearly every trailer that Keystone built prior to the "giggy box" had a 4x4 galvanized junction box on either the trailer A-frame or on/in the pinbox. It's been the standard part to connect the trailer umbilical to the trailer distribution wiring for more years than I can recall.

Every trailer that I've had, from a 1972 Jayco to present (with the exception of Airstream) has used that type interface between the unbilical 7 pin cable and the trailer wiring.

**chuckster57** · 07-06-2022, 09:11 AM

Quote:

Originally Posted by JRTJH

^^^ This, plus, prior to about 2016/2017, trailer wiring "color coding" used standard house color codes. In other words, black was HOT and white was NEG/NEUTRAL. Older trailers, like the OP's 2001, probably have "black POS cables and white NEG cables".

Of course, a previous owner could have/might have changed all of that with "owner upgrades"...

I'd remove trailer power, dig into that junction box and see where the "cable in question" is physically connected. Knowing that may provide the answer, or at least a head start on where the cable goes.

I learned last month that you can’t always count on anything being “standard”. Working on 2018 or newer class A. Had to rewire the antenna booster plate and found the white was hot and the black was ground. Took me 10 minutes to find the fuse panel

Team707 · 07-06-2022, 10:42 AM

Quote:

Originally Posted by wiredgeorge

Fella owns a Tailgator older toy hauler and hasn't mentioned what year but probably pre-solar wired. A signature with year, make and model of the camper and same for the tow vehicle would help give context to answers to his question. Under UserCP and then save.

Sorry, I thought that went in when I filled it out at sign up, but I've added it now.
Anyway it's a 2001 Keystone Tail-Gator 255RR - not pre-wired for solar.

The ring is too small for the battery terminals by a long margin, which is what threw me for a loop.

If I test continuity to ground and it has it, then it's a ground wire for some circuit or another. If not, then it's a power feed for somewhere, and I have to connect it to a power source, right?

Team707 · 07-06-2022, 10:47 AM

Re - trace the wire: I did take the cover off the junction box, this black wire joins two other black wires that go back out through the box again via a heavily insulated cable that contains a tonne of other wires too, so I wasn't able to trace it. I'll get back under after work and have another crack.

Thanks heaps to BSmith for the detailed testing guide, I was thinking along those lines but needed technique help. I'll report back soon my dudes!

Team707 · 07-06-2022, 06:03 PM

So, I checked for continuity to ground - there was none.
I checked the junction box again, the black comes in from the trailer pig tail (black is apparently the charge from the car), and then joins two other mystery black wires both of which are connected to this.

I determined it's the charge wire for the battery from the car. I installed it on the circuit breaker as it fit there, the wire is the right length, and there is literally nowhere else it either fits or within reach of the cable.

Photo attached, thanks for everyone's help - hopefully I'm right!

wiredgeorge · 07-06-2022, 07:25 PM

Quote:

Originally Posted by Team707

So, I checked for continuity to ground - there was none.
I checked the junction box again, the black comes in from the trailer pig tail (black is apparently the charge from the car), and then joins two other mystery black wires both of which are connected to this.

I determined it's the charge wire for the battery from the car. I installed it on the circuit breaker as it fit there, the wire is the right length, and there is literally nowhere else it either fits or within reach of the cable.

Photo attached, thanks for everyone's help - hopefully I'm right!

Hopefully you have a fire extinguisher in your camper when you power up the camper!

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