Battery is gone, brakes and taillights not working now

Hijacking this thread momentarily to say hello to Cow.  How's it going in your part of the country?  How's your trailer coming along?

Houston, we have a problem.

I was able to get inside the trailer today to look around. 

Keep in mind, I don't know much about wiring, other than basic circuitry and I have  never wired a trailer or a vehicle. Also, I have never had an issue with the taillights, marker lights or brake engagement in the past.  I have owned the trailer for almost 9 years.

In trying to find the problem, I checked all the fuses inside the trailer and all are intact.
I checked the inline fuses at the battery terminals(on the wires that go back to the hitch) in the TV.  One is a 15amp and the other is a 30 amp.  The 30 amp was blown.  I replaced it with a new one.

Lights were still dead in the water.

I checked and rechecked all my connections at the rear of the tow vehicle and the connections were solid.  Still dead in the water.

I bolted the battery terminal wires in the trailer together hoping to complete the circuit.  No go.  I even clicked the inverter to the off position. There is a circuit breaker on the inverter.  When I push it down, it sounds like it resets inside.  I hear a click.

I will put the battery back in tomorrow, but I don't think that's the issue.  I will also add some dialectric grease to the harness that goes into the side of the trailer tongue even though it fits snug.

My trailer has been mothballed on jacks for a year in a carport protected on three sides since  just before my shoulder operation in July last year.  Since then, the alternator was replaced on my tow vehicle and I removed the battery in the trailer.  Nothing else has changed. 

Also, I have towed my trailer in the past with the battery wires disconnected in the trailer where they attach to the terminals in the battery to ease the load on the alternator and I had my lights and brakes working at that time, so that tells me that the circuit is probably closed regardless of whether the battery is connected or not. 

So, is the problem in the TV wiring?  I couldn't get underneath my van tonight as it was getting dark.  Maybe something happened to a wire somewhere.  The brake controller does not indicate a connection.

I am befuddled.  We are scheduled to leave on our camping trip on 4 days...

Hey Vikx,

Thanks for the lead, no pun intended.

I researched this and found that it might help to have the trailer hitched up to the tow vehicle when testing...

I will try that later today after the sun rises and report back.

cheers,

Rod

Rod, It is possible that the fuse blew again as soon as you tried your lights again, before hooking up. A dead short or bad ground will pop 'em as soon as you try to light 'em up. It seems like you have a ground issue and the ground is completed by the trailer being connected to the tow vehicle that is supplying the power. Make sure you clean off the hitch and ball well to keep good contact there. I would also recommend checking the spots where your system grounds to the frame, including the grounding that runs from your plug-in wiring. If there is a break in the ground between the plug-in and the lighting system onboard the trailer, then it will cause a short-circuit, overheating the wiring and blowing fuses.