No 12V power

annmarie · 05-20-2020, 05:39 AM

Our travel trailer is plugged into shore power and all of our outlets work but nothing operating on the 12v system works (lights, awning, slide out, water pump, etc).

A little background here... we may be operating off the original owner’s battery which would be 5ish years old now. We probably didn’t store it right from November to April (it just sat- no trickle charging - won’t do that again). When we dewinterized it the battery was working (although our water pump would provide sufficient pressure but then continue at a low hum with an additional hissing sound but never shut off). We plugged it in and it has now been sitting for a couple weeks. Just went back to check on it yesterday and discovered that nothing beside our outlets was receiving power.

Any ideas on what’s going on here or troubleshooting steps? I’m hoping it’s just the battery and not an issue with the converter.

notanlines · 05-20-2020, 06:10 AM

First thing is to make sure your converter is getting 120 volt power. Then use the volt meter and check To make sure there is the 12 volts coming out of it. At that point we can go further.

Logan X · 05-20-2020, 06:13 AM

If you are plugged into shore power everything should be working. You may have blown a fuse or something like that. I would start at the battery with a volt meter. Disconnect the battery and put the volt meter on the disconnected cables. With the trailer plugged in it should read 13 volts or better. If it doesn’t, there is a probably a problem with the converter. If the voltage reading is good, it is a problem with the battery, a connection somewhere, or a fuse.

Don’t run the slides or any other high power items without a good battery installed or you could damage the converter.

If the voltage is good there, reconnect the battery (that battery is probably dead and needs to be replaced) and make sure all of the connections are clean and tight. Check where the negative cable grounds at the frame to make sure it’s clean and tight. Check the connections at the auto reset breakers to make sure they are clean and tight. Check all of the fuses in the power distribution panel.

**JRTJH** · 05-20-2020, 06:19 AM

You probably hooked up the battery "backwards" and blew the two reverse polarity fuses on the converter. Check your battery connections. BLACK to + and WHITE to - is correct. If it is hooked up in reverse, you need to correct the wiring and then replace the two fuses. They're the red 40 amp ones.

If the wiring is correct and you don't have power, it may be a battery issue. Completely disconnect the battery from the trailer, make sure the battery cables are not touching the trailer (not grounded) and plug the trailer into shore power. You "should have 12 volts" from the converter to operate lights, etc. DO NOT ACTIVATE ANY SLIDES WITHOUT A FULLY CHARGED BATTERY CONNECTED"

travelin texans · 05-20-2020, 08:26 AM

Is the factory battery disconnect set in "USE" or ON?
If it's set to "STORE" or OFF the battery will not charge when plugged into shore power.
Check the water levels in the battery & top off with distilled water.
But with sitting all winter with cables connected I'm betting the battery is toast.

annmarie · 05-20-2020, 11:37 AM

The battery was removed and stored separately all winter.

We did accidentally hook it up backwards in our dewinterization process. We figured that out when our awning button was in for out and out for in. We switched it to the correct + - and still had power. If a fuse had blown, that would have happened immediately, right?

Unfortunately our TT is not on our property so we can't just pop out there quick and troubleshoot as we go so I am trying to gather as much information before we make a trip back.

As of now we will plan to check fuses, voltage, and possibly replace the battery if needed.

**JRTJH** · 05-20-2020, 12:07 PM

Quote:

Originally Posted by annmarie

The battery was removed and stored separately all winter.

We did accidentally hook it up backwards in our dewinterization process. We figured that out when our awning button was in for out and out for in. We switched it to the correct + - and still had power. If a fuse had blown, that would have happened immediately, right?

Unfortunately our TT is not on our property so we can't just pop out there quick and troubleshoot as we go so I am trying to gather as much information before we make a trip back.

As of now we will plan to check fuses, voltage, and possibly replace the battery if needed.

No, it would not have happened "immediately". The reverse polarity fuses "protect the converter electronics" from the reverse hookup effectively disconnecting the converter from the RV system. As soon as you touch the battery terminals, those two fuses will blow. Then, when you connect the battery correctly, the battery (not the converter) will provide correct voltage until the battery is discharged at which time "nothing works" until the reverse polarity fuses are replaced and the converter again starts providing power to the system.

Right now, your reverse polarity fuses are blown, your battery is dead and your converter is "humming away doing nothing".

Once you replace the two fuses, you'll probably find that the battery is shot, or it won't accept a full charge since it's been "dead for so long"...

notanlines · 05-20-2020, 12:35 PM

AnnMarie, I couldn't agree more with John's synopsis. Go prepared with new fuses (four would be good) and a new battery that has been charged before you go. You'll be set AND you'll have two spare for when that sorry dog husband of yours hooks the thing up backwards again!

(I'm just going by what would be said in most households!)

**flybouy** · 05-20-2020, 01:08 PM

Jim, I think in most households that dog's parentage would be in question.

HappyCamperMN · 05-20-2020, 02:31 PM

Where are these red 40 amp fuses usually?

I have two "terminal blocks" on the frame where all the battery connections are. They happen to be red and have a plastic cap to keep the weather out.

Or are they normally found in/at the converter? Which I assume is accessed by removing the plastic cover for the electrical panel.

...asking for a friend

**JRTJH** · 05-20-2020, 02:48 PM

I assume that you have a 30 amp WFCO power system. Open the door to your power center, where all the fuses and circuit breakers for the main panel are located. On the right side you'll see a vertical stack of 12 volt fuses. Just to the left of that vertical stack will be two red 40 amp fuses. Those are the reverse polarity fuses.

You can see them clearly in this photo.

The "mini-breakers" located on the front A-frame bulkhead are there to protect the trailer wiring at the battery feed. They are not associated with the reverse polarity protection.

HappyCamperMN · 05-20-2020, 02:56 PM

Quote:

Originally Posted by JRTJH

I assume that you have a 30 amp WFCO power system. Open the door to your power center, where all the fuses and circuit breakers for the main panel are located. On the right side you'll see a vertical stack of 12 volt fuses. Just to the left of that vertical stack will be two red 40 amp fuses. Those are the reverse polarity fuses.

You can see them clearly in this photo.

The "mini-breakers" located on the front A-frame bulkhead are there to protect the trailer wiring at the battery feed. They are not associated with the reverse polarity protection.

Thanks for the quick reply! I've got a 50-amp panel WF-8930/50 which through searching I just discovered...

Quote:

The WF-8930/50 Series Distribution Centers DO NOT have a converter installed within the enclosure. Power is supplied to the WF-8930/50 Series Distribution Centers from an external converter/charger, WF-9800 Series Converter/Charger for example, located elsewhere in the RV. Reverse Battery Protection will be provided by that unit. Consult that converter/charger’s manual for location and replacement instructions.

As I hear the converter fan running in the general area of the shore power feed and the electrical panel, I'm guessing my converter and it's fuses are located inside the cabinet and behind the electrical panel...

notanlines · 05-20-2020, 02:58 PM

I loved the “I’m asking for a friend”

HappyCamperMN · 05-20-2020, 03:01 PM

Quote:

Originally Posted by notanlines

I loved the “I’m asking for a friend”

I've hooked up the battery many a time... Unfortunately this time I was talking to someone while doing it and hooked it up backwards.

**JRTJH** · 05-20-2020, 03:13 PM

Yes, if you have the 50 amp power center, the converter is located behind the power center, usually "right behind it". If you remove the front panel of the power center, you'll see 4 mounting screws. Remove them, the entire power center will slide forward. There is (almost always) enough wire/cable to pull the power center out of the way to access the converter.

Since there are exposed terminals and exposed wires on the back of the power center, be sure to disconnect shore power and the battery before removing those 4 screws... The last thing we need is for your DW to make the next post asking, "How do I get my DH disconnected from the power center? He's glowing bright orange and shaking violently."

HappyCamperMN · 05-20-2020, 03:14 PM

Unfortunately no help from the manuals that came with the unit. The installation manual that I have is for the same 30-amp panel that JRTJH shared a picture of.

Looky looky... All these converters have fuses on them. https://www.rvweb.net/best-rv-converters-reviewed/

Not that I have one of those, just looking for ideas of what I might be up against.

HappyCamperMN · 05-20-2020, 03:46 PM

suspicions confirmed...

(and yes, I did remove all power before venturing back into the dangerous areas)

https://drive.google.com/file/d/1N95...ew?usp=sharing

Is inside the cabinet and ~2-ish feet behind the distribution panel that only has an opening big enough for me to get my arm into about a foot...

https://drive.google.com/file/d/1_hx...ew?usp=sharing

[apparently I need to work on my photo posting skills]

John, it does look like there is enough slack wire back there to slide the panel out, thanks as always for the the sage advice!

**JRTJH** · 05-20-2020, 04:30 PM

Where is "rubber arm man" when you need him ??? I don't know of any easier access for your trailer. On some of the larger fifth wheels, the power center is inside the trailer and the converter is mounted behind the passthrough wall. The only "problem" is having to remove most of the cargo to get to the panel that's held in place with 4 screws. Once the panel is removed, easy access... Just all that cargo to put back into the trailer when you're done with the 30 second job...

HappyCamperMN · 05-20-2020, 06:22 PM

Rubber arm man would be handy... There is no other access. The distribution panel comes out easy enough and yes fuse(s) are blown. I only took one out. Of course the converter is in sideways and there isn't much clearance on the fuse side. Tough to maneuver. Coming out is easy, getting lined up to put back in not so much. Off to find me some 40 amp fuses tomorrow. Enough to have at least 2x spares me thinks...

HappyCamperMN · 05-23-2020, 05:27 AM

Thanks for the help. I picked up some fuses, got them installed and all is back to normal. Camper is prepped and ready to begin 2020 adventures next weekend.

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