No 12 volts from Tow Vehicle ??

[jp279]

2006 JayFlight 30.5 RLS

Battery went dead on trailer, so I thought the 12 volts from my TV would be able to power the 12 volt accessories, but it didn't.
If I put a voltmeter on my 7 pin plug on the TV I got 12 volts.
I was able to verify that I have 12 volts on the trailer cord where it goes in the trailer by the 5th wheel hitch.
I put a voltmeter on the power center, no 12V.
I took the battery out of the trailer and I have no 12V power inside the cabin.

I put a new charged battery in the trailer, checked voltage, got 12.8. When I hooked the TV up to the trailer via the 7 Pin connector, I expected the voltage to rise, it didn't.

It's almost like there is a break in the wire between the hitch and the power inverter which is located in the back of the trailer.

Could a bad ground between the trailer and TV be possible?

Any thoughts or information would be appreciated.

[Threebutchers]

Did you check for a blown 30A "Reverse Polarity" fuse in the converter? There may also be a blown fuse off the positive battery terminal between the battery and the exterior front main junction box.

[jp279]

Yes, I checked those fuses, they are both good

[Threebutchers]

Sorry that didn't help....(next man up)

[Jmooney]

How about reference to ground in the trailer. ( main ground lug to trailer frame , and ground wire back to power center )

[Jmooney]

Let's us know what you find

[troutslayer]

You may have a bad converter. A 2006 model may be due for a new one.

[tnchuck100]

Pin 4 is 12V. Pin 7 is for backup lights.

http://www.etrailer.com/faq-wiring.aspx

[Mustang65]

- Check the 12VDC lead on the TT's charge controller that comes from the battery, this connection may be lose or not even connected. Same with the controllers ground lead.
- If you know a little about electricity, follow the fused lead from the battery into the electrical box where it goes into the TT. Open the box and make sure that the wire from the battery is connected to a wire that goes into the TT. If there is a wire nut on the lead check for a good connection and also check the voltage there.
If all else fails,
- Try this, disconnect the battery from the TT (pull the 30 amp fuse by the battery box), disconnect your shore power cable, and your TV cable. Now there should be no voltage in the TT. With a digital voltage test meter, put it on Ohms (resistance) and put the red meter lead into the fuse clip on the TT side, not the battery side. Ground the black meter lead to the frame. Do you get any resistance reading? Next turn on your TT's interior lights, the resistance reading should be different.
If not, your 12 volt battery feed is open somewhere between the battery fuse and the charge controller, or the lead fell off the charge controller.

Good Luck
Don

[jp279]

Originally Posted by Jmooney

How about reference to ground in the trailer. ( main ground lug to trailer frame , and ground wire back to power center )

The 7 pin cord that connects the trailer to TV has a ground wire that grounds to the 5th wheel hitch on trailer, that appears good.
I thought the ground wire from the converter to the frame might be bad, unfortunately the trailer has a sealed underbelly. I was able to open an access panel that was about two feet from the ground lug, it appears to be secure, (OK).

So to recap, with trailer battery connected, I have 12volts inside the cabin.

With battery disconnected, and 7 pin plug connected to tow vehicle, no 12 volts inside the cabin.

it appears the ground is good at the hitch end and at converter. I'll have to check the resistance on the +12v wire on the 7pin trailer plug to the converter.

[Mustang65]

Based on what you have already done, lets give this a try.

FIRST things FIRST!!! Pull the TT's 30 amp fuse by the battery box, pull the shore power connection and unplug the TT plug from the TV.

Follow the black TT cable that hooks up to the TV, back into the electrical box (usually mounted on the frame somewhere, not sure about a 5th wheel). Open the electrical box and find the 12VDC lead from the TV.

Isolate the TV 12VDC wire from the wire nut that connects it to the TT's battery controller and TT batteries.

Protect the other wires from being able to short out to ground.

Check pin 4 of the 7 pin TV receptacle (just check it again, could save a headache) to make sure you have 12VDC. One more test on the TV receptacle, if you have a 12VDC bulb with leads on it see if you are getting a strong 12VDC from the plug. Not saying that somewhere on the TV could be a corroded connection (this will give you 12VDC with no amperage behind it).

Plug in the TT plug into the TV. Check the TV wire in the electrical box to see if you have 12VDC. If not you may have a bad or corroded plug/connector or no electrical connection on the wire from the TV (open circuit).

While you are watching the volt meter have someone wiggle the TT cable that connects to the TV (at the TV) to see if it may be a lose connection/wire.

This will at least let you know if you have 12VDC hitting the splice/wire nut in the electrical box. Based on the tests that you have already performed it may be an open cable or bad connector.

Just be careful. Let me know if this does not locate the problem, we can do a few more things.
Don

[lx22f/c]

Like said above check your tv 7 pin plug!!!! I have had to replace mine once already. A very common problem. Good luck