lost all 12 volt power

Tavery

I had 2018 t@g plugged into inverter generator as a test of generator. All worked fine. And unhooked generator

Battery was disconnected at the time

I reconnected battery, no power. 30 amp Fuse link at battery cable had blown.

Replaced with new fuse. No power

New lead acid battery is at 12.8

Connected to shore power. All is well there.

Any idea?

Sharon_is_SAM

I assume all your lights, fan, etc function on AC if all is well on shore power. There is a reverse battery fuse in your converter panel. Check/change that.

Tavery

If this is the 30 amp main 12 volt fuse yes. Is appears good.

JamesDow

Tavery,
Have you checked the fuses at the converter inside of the trailer? You have four that could cause the issue. If all four (1-4) are blown, you would not have any 12-volt power from the battery to the accessories.
The 30-amp (Reverse Battery) fuse should not affect the 12-volt system from the battery. It can even be pulled with no change. To have blown the 30-amp fuse at the battery is odd, but things do happen for little to no reason. My 10 Amp fuse from my TV to the trailer blew shortly after I installed the dedicated wire from the TV battery to the trailer through the 7-blade connector. I found no reason, besides likely faulty fuse to start with. Have never had a problem since it was replaced.
If the fuses are blown, I would replace one by one to see if a problem circuit can be isolated. Good Luck

Sharon_is_SAM

If the lights, fans and other 12 v devices work on shore power, then the individual 12 v fuses can’t be blown.

Sounds like you had a surge from the generator - toasted your battery fuse. If you have a battery disconnect switch, can you check to see if it is intact and able to carry current. Battery leads intact? Follow your battery leads to your junction box - still have current?

Tavery

I discovered that the 30 amp reverse battery fuse was faulty,(blown but not visible?) replaced it with new and I now have 12volt power on battery also, rather than on shore power only.

Sharon_is_SAM

Easy fix! My next suggestion was to make sure your battery wires were not crossed - it does happen!

The fuse lights require power. They can be difficult to see.

JamesDow

Tavery,
F.Y.I.
The Installation and Owners Manual for the WFCO WF-8725 converter indicates “If fuse(s) are blown this means the RV Battery was accidentally connected in reverse either at the battery or at the converter. Connect properly then replace the fuse(s).”

JamesDow

Tavery,
F.Y.I.
The Installation and Owners Manual for the WFCO WF-8725 converter indicates “If fuse(s) are blown this means the RV Battery was accidentally connected in reverse either at the battery or at the converter. Connect properly then replace the fuse(s).”

"IMPORTANT: These fuses protect converter from damage in the event RV Battery is accidentally
connected in reverse. A reverse battery connection even for a second is the only thing that will blow
these fuses."

JamesDow

Tavery,
Just spoke with tech support at WFCO and they indicated that if the 30 Amp Reverse Battery fuse is blown then the one above should also be blow. You may want to double check. They also confirmed my observation that a pulled or blown 30 Amp Battery Reverse fuse should have no effect on the continued functioning of the Trailer battery operated 12 volt accessories. The fuse only protects the converter.

SueBHunny

I just need to send a thank you to the folks on this forum. Last night this thread helped me to restore 12V power after it seemingly stopped altogether. A new fuse, and I'm back in business! You all make me feel like I've got this thing under control.

JamesDow

Glad things worked out.

DougWorth

I just spent two days of head-sctratching with the same issue. I should have asked all of you first thing. That second fuse (the 20amp) did the trick. Thanks to everyone on this site for all the help and inspiration!

Bgreen

Guys, I was following this as I was dealing with similar symptoms. My scenario was that recently replaced the battery with a new one of the correct size and before I had a chance to run it I noticed the 20 amp fuse on the negative side of my battery was blown. I replaced it only to see that my 20 amp in my panel was blown. After replacing them both. I disconnected my house AC and connected to my travel vehicle and headed out. I got to my camp spot and no d/c power to run my refrigerator. This was after switch was turned to the on. I had also brought up a small generator and powered up the T@G from it. After checking I saw that both 20 amp fuses had blown again. Still no D/C power to run the refrigerator. When I got back home I read your comments and have tried several scenarios to no avail. I am thinking that my switch may be faulty. Thoughts?

Bgreen

I forgot, I have a 2017 T@G XL Outback. We generally use shore power where I include the surge suppressor in line. I just keep the battery trickle charged at home but recently my battery was not hold a charge.

Sharon_is_SAM

The battery fuse is typically off the positive terminal. I think your battery fuse should be 30 amps, too.

Bgreen

I will check it out and see that it is done that way. It was set up that way but until recently we had always shore camped and when we did boondock we wrote it off to a low battery.

SueBHunny

I am so happy that I always have this forum to turn to!!! My dealer didn't complete the work they were doing on my T@G (long, different story that ends with my needing to find a new place to have work done), and nothing electric was working unless I was plugged into AC. Long story short, I changed all the fuses and disconnected and reconnected the battery. And now I can comfortably go on my trip this weekend. And I owe it all to the wisdom of this group. THANK YOU!!!!