This is almost too embarrassing to post, but I need help in hopes of salvaging our weekend trip. I replaced the trailer-side 7-pin connector on my TT today without disconnecting from shore power, unplugging or turning anything off or otherwise taking any precautions. Long story short - in the process of that I shorted the 7 wires together as I was feeding them through a rubber boot on the new connector. Now, none of the 12V items or outlets in the trailer work. Also, the A/C does not come on (the breaker is in the on position). The breaker to the microwave was turned off at the time I shorted the connector wires, and when I flip it to the on position, the microwave works. The 110 outlets in the trailer are live. At the electrical panel, on the 12V side, none of the fuses are blown, including the two large ones. None of the 110 breakers are tripped. None of the three fuses on the PD9180 charger are blown. The large fuse in the cable between my battery bank and the PD9180 is not blown. (Oddly, after I pulled and replaced the fuses in the charger, the pendant began blinking rapidly, even though it has been plugged in and charging for a couple of weeks - I don't know if that is relevant to diagnosing the problem or not.) I'll be very grateful to hear any suggestions on what I should check. I have a multimeter. Thanks in advance.

Sometimes there is a hidden in line tiny breaker on the 12v system with a small button to push. Does not look like a breaker.It is possible the AC does not come on because the thermostat needs 12v from the furnace, but the 12v system is down.Just as a starting point what is the voltage at the battery, and at the 12v output of the converter?Jim

Are you checking these fuses with a meter? A good visual inspection does not necessarily mean a good fuse. I've been burnt by that in the past.

Jim, thanks for replying. Your comment about the inline fuse reminded me of one I'd seen. I just looked again. It's a grey plastic box, maybe 1 1/2" by 1/2" x 1/2" with two poles, it says "SHORTSTOP 12/24V K36 30A", but there is not a button on it to push. I'll be back with those voltages. Thanks.

I was only doing visuals on the fuses. I will go out and check continuity on those. Thanks, mena661.

tom496 wrote:Jim, thanks for replying. Your comment about the inline fuse reminded me of one I'd seen. I just looked again. It's a grey plastic box, maybe 1 1/2" by 1/2" x 1/2" with two poles, it says "SHORTSTOP 12/24V K36 30A", but there is not a button on it to push. I'll be back with those voltages. Thanks.Sounds like that kind of sneaky breaker with a hidden tiny button everyone gets bitten by. If there is no obvious way to reset it (some are self resetting)' check the voltage at each pole relative to ground and from pole to pole (on the off chance that somehow the ground connection opened up).Jim

Urgently Need Help Diagnosing Dead Electrical System

ken_burke
Explorer
Jun 08, 2013
tom496 wrote:
There is continuity across the "shortstop" fuse.

I am getting 13.42V at the posts in the electrical panel where the cables from the converter are connected. I will try to post a photo.

Well you could have a bad converter. The 12 volts you are reading could be coming from the TT battery while the converter is not putting out.
If you can, disconnect the 12 volt batteries. Turn on some DC loads, i.e. lights. If the converter is working you will have DC voltage. If nothing is working the converter is shot.
I hade had a converter that worked part time, but not when a lot od DC devices were connected.
If it is a bad converter, they are not that hard to replace.

ken
tom496
Explorer
Jun 08, 2013
I replaced the connector because of the electric brakes being weak. I'd had the experience in the past of trailer brakes being weak the first time out for the season, but this year it persisted. I examined the connectors and the one on the TV is in great shape, but the trailer side connector was corroded and had several bent over and otherwise damaged blades. I decided it needed to be replaced regardless of whether it was the cause of the brake problem and in the hope it would solve it. I'll know that in the morning when we head out.

The alternate path theory sounds plausible. It's tough to believe the cause of the white neutral wire coming loose was the short in the connector wires.
HiTech
Explorer
Jun 08, 2013
Great! Per the above - what caused you to need to replace the connector in the first place? Burned contacts or melted plastic around the ground lead maybe?

Jim
Artum_Snowbird
Explorer
Jun 08, 2013
Yippee... and enjoy your trip.
tom496
Explorer
Jun 08, 2013
I connected the white neutral wire to the terminal block labeled C in my photo -- there are two connection lugs on that block. All of my 12V appliances work again! The white wire did not show any signs of melting or burning that I could notice.

I held my breath and plugged the 7-pin connector into the TV. No problems so far.

The whole thing still does not really make sense to me, but bottom line - we're going camping! For that we thank Mike and the others who posted here. This definitely would've been a weekend at home without you. Thanks again and have a great weekend!
HiTech
Explorer
Jun 08, 2013
I wonder if it was disconnected and the trailer connector was providing ground via an alternate path?

What was the original reason for replacing the connector?

Jim
Artum_Snowbird
Explorer
Jun 08, 2013
And also remember, there may be a terrific amount of current waiting to get "home" when you connect that wire. You might think of cutting off the battery and being off shore power or it will spark a lot when you plug it in.
Artum_Snowbird
Explorer
Jun 08, 2013
If the stripped end looks rather burnt, that is indeed your problem. I can't tell you where it connects to C, but I can tell you that that is the return for all your devices. If it's laying on the floor, then somehow it used to be connected... If it looks burnt, overheated, or the insulation is melted, then it carried too much current and that current might have also run to ground and blown that connection too before it blew off.

You may get your devices back, but I would still be very wary of your 7 pin connector and the wires leading to where the fault occured.
tom496
Explorer
Jun 08, 2013
OK, as Mike suggested, I checked voltage between the white lead and my C terminal and there is indeed 12V. I will make that connection, and connect the ground wire to the terminal on the rear of the fuse panel, and report back.
tom496
Explorer
Jun 08, 2013
It looks like you are onto something, Mike. I looked into the space behind the fuse panel and, viola, there are a half dozen white wires converging into a wire nut, from which a three foot length of white wire emerges which is long enough to reach the fuse panel but is not connected to anything -- just a stripped end resting on the floor. There is also a bare copper ground wire emerging up through a hole in the floor which also is not connected to anything. I also noticed that the ground terminal on the back of the fuse panel does not have a wire connected to it.

So, does the white wire go into the empty spot on the C terminal block?

By the way, if this is the problem, I don't understand why the 12V appliances all worked fine until I changed out the trailer connector today.

Thanks again, Mike, and others who have responded.

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