No DC power when off shore power

[Tammy Lou]

I'm looking for DC power troubleshooting help. I recently bought a 2001 T-1950. The seller said the battery was dead and needed replacement. A battery shop replaced the battery. I tried to turn on lights while there and none came on. The tech tested the battery and checked the converter box and said "there is continuity at the converter box".

Camper: 2001 T-1950
Power Center Model: World Friendship Co.'s WF-8955PEC

I've been doing a bit of youtube research and still can't figure out how to get DC power without shore power. Everything still works when hooked up to shore power. None of the little red lights are lit in the converter box that would indicate a blown fuse-see pic. The seller said that the master power switch is the first switch inside the door, so I've got that flipped on as I troubleshoot, and still no DC power.
I traced the wires back from the battery to where they enter under the floor and found the small wooden box with two 30 amp fuses under the couch seat. One fuse was blown; I replaced both. But alas, still no DC power.
Learning that a poor ground could be the problem, I checked the forward underbelly area and here is a pic of what I believe is the ground. I don't know what I'm looking for as to a ground. I see a bit of rust but the metal seems to be touching metal. Are there other grounds or fuses I should look for?

Thanks in advance for any help!
Tammy

[JohnB]

Hi Tammy,

You have done well trying to sort this out and provided a good start to help with the troubleshooting.

The WFCO power center was not the original Sunline-installed power converter, so it was replaced along the way. They are not bad converters per se but have been known to start having problems in the 10 to 15-year time frame. This is not your immediate concern; I mention it as someone has been into the power center and changed some things, so we might need to sort out what they did.

You mentioned this by the prior owner,

The seller said that the master power switch is the first switch inside the door, so I've got that flipped on as I troubleshoot, and still no DC power.

The "master switch" inside the door is new or different from what Sunline would have provided in 2001. Can you post a picture of what they are referring to?

Sunline started in mid-2004 models to install a master battery disconnect switch on the trailer frame header behind the LP tanks. This disconnect was a high-power rotary switch that unhooked the battery when the camper was in storage so it would not drain the battery close to dead in a few weeks when not camping. Since the camper is new to you, I will explain this drained close-to-dead event so your new battery does not experience the same issue once you fix the problem.

There are small DC power loads that have no on/off switch, like the LP gas detector and the lights on the radio. There are at least two other loads with switches that can be left on, not knowing it, like the little green light on the rooftop antenna booster indicating the booster is still on and the big one, the climate control rocker switch for the fridge. That climate control switch should always be off unless you have a large humid condition and find ice forming on the freezer gasket freezing the door shut. They heat the gasket to have it not freeze the door shut, and anything that makes heat on DC power drains a battery fast.

How most folks deal with the draining battery problem without a battery disconnect switch is to unhook the battery negative terminal while the camper is in storage. This can be a pain as you have to deal with the battery cover and, worse, the cover strap, but it does work. For safety, unhook the negative wire instead of the positive wire for this storage draining issue. The negative wire is attached to the camper frame, called the ground wire or frame ground in DC circuits. Since the negative is common to frame ground, no sparks will come if your wrench or pliers undoing the negative cable touch the LP tanks or the camper siding. The positive wire can create large sparks if they touch the camper if the negative wire is still attached.

This leads to that master switch the prior owner is talking about. We have to figure out what he did to create that. Take a few pics of the battery area wire connections, and near the battery, he "might" have installed a high-power solenoid contactor (switch) that uses a small on/off switch inside the camper or did something else to create a master switch.

Your hunt for the wooden box was a good one. Those two green fuses in the box:

1. One fuse is to protect the battery, the power converter, and the wiring between the two. If that is blown, no battery power will pass inside the camper.

2. One fuse is to protect the truck, the 7-wire cord wiring, and the battery; we call this the truck charge fuse. This fuse will not affect power from the battery getting into the camper, but when blown, the battery will not charge from the truck when towing. This fuse can be blown, and the owner never realizes it until they find out their camper battery is not charging when hooked to the truck. It can be years blown, not found, pending how the camper is used.

Do you know which fuse was blown that you replaced? They may not be labeled, but we can tell by the thickness and color of the wires attached to the fuse holder and which is the truck charge fuse etc.

This pic of yours,


Gently spread the wires apart so you can see, take a pic, and look at the wires attached to the black fuse holders. The fuse holders often have orange wires that are wire-nutted to the camper wires. The truck charge fuse could be a black wire going into the camper's floor, and the camper power converter protection fuse would be wired to a large, big thick red wire. If you cannot figure this out, post a pic.

If the truck charge fuse was blown, this is not your current problem; the prior may have had it blown for years. If the camper power converter protection fuse were blown, that would be a problem as something caused that fuse to blow. We need that info to help solve this puzzle.

This ground wire connection (battery-negative) does not have heavy corrosion and is most likely not your problem.


The individual circuit fuse lights on WFCO fuse board will only work when the power is on. Since you are not on shore power or battery power, none of those red lights will be lit. Since your camper works with the shore power plugged in and you have no red lights, the odds are good; there are no blown fuses in the power converter.

When your battery tech stated this,

The tech tested the battery and checked the converter box and said, "there is continuity at the converter box".

. The word continuity can mean a few things, pending the context they are using it. That would be very helpful if he had said there are 12 volts at the power converter. But he picked the continuity wording, and if you have no power in the camper while at the battery place, with the new battery in place, something does not add up with that wording. Continuity in the electrical world means being connected, and the wire path is good. Something is off with this continuity statement, but it may explain itself once we find the problem.

I'll ask, as this may get more technical pending what we find, do you or a friend have a volt/ohm meter and know how to safely work on electrical wiring, home electric, or auto electric?

Here is something else, you said you have no lights. Did you try something else that runs on DC power, try the water pump, look at the radio display, or turn the fridge and open the door to see if the light inside is on? You might have an issue that other DC items work but not the lights. This is essential information to know and gives credibility to the tech's continuity statement. If you have a specific power in the camper that does work and not in others, the direction changes in the troubleshooting.

I hope this helps,

John

[Tammy Lou]

Thanks John!
No DC power to anything...water pump, radio, fringe light, etc.

As to the "master switch", I now believe what the seller was referring to was the wall switch, which (when I hook into shore power) only powers ceiling lights whose rocker switches are left in the on position. It is actually the second switch next to the door.
I've included a pic of the wall switches.
Great info about DC power loads and disconnecting the battery negative wire for storage...thanks. As a matter of fact, I did find the fridge climate control switch in the on position and turned it off before I got the new battery installed.

I haven't found anything looking like a switch near the battery. Including pics of what is there. I had the emergency break-away brake replaced before getting a new battery and included pics of that.

It looks like the fuse that I found blown is the camper power converter protection fuse as I believe it is blue nut-connected with the thicker red wire, although it is difficult to see. There are red wires going into two blue nuts. Including pics in the next post as I'm at max upload.

Of note is that prior to replacing the battery, I was at a campground when a big storm hit and the power went out. Of course the DC power (when off shore power) wasn't working before that, and I attributed that to a dead battery. Additionally, I heard a little spark sound today when hooking to shore power using a 30amp to 110 tail and a 3-prong extension cord at my home.

I have the three meters pictured left behind from my ex-husband, but I've never used one of these types of meters. I have replaced outlets, switches, and fixtures at home in the past.

Thanks again,
Tammy

[Tammy Lou]

Here are pics of the contents of the wooden box under the couch seat. There are three blue nut and three white nut connections. (Repeating previous post)...It looks like the fuse that I found blown is the camper power converter protection fuse as I believe it is blue nut-connected with the thicker red wire, although it is difficult to see. There are red wires going into two of three blue nut connections.

[Tammy Lou]

I just thought of something else. My mechanic told me this morning that if the emergency break away plug isn't fully seated in the unit that this would activate the brakes and drain the battery quickly. I found the plug out of the unit, and pushed it back in. The thing is is that I don't remember hearing the brakes engage as I pulled out the brake plug when last disconnecting the camper a few days ago. I read somewhere that the emergency brake system requires battery power to activate. Is that so?

[JohnB]

Originally Posted by Tammy Lou

I just thought of something else. My mechanic told me this morning that if the emergency break away plug isn't fully seated in the unit that this would activate the brakes and drain the battery quickly. I found the plug out of the unit, and pushed it back in. The thing is is that I don't remember hearing the brakes engage as I pulled out the brake plug when last disconnecting the camper a few days ago. I read somewhere that the emergency brake system requires battery power to activate. Is that so?

Hi Tammy,

Let's do this simpler question first.

Your mechanic is correct; if the emergency breakaway switch is not fully seated, that switch will apply full power to the camper brakes, and it can drain your battery quickly. Quickly means if your new battery is fully charged, the brakes will pull 12 amps constantly, and in about 4 hours, the battery can be 50% or more discharged.

Now to what you can hear, assuming the brakes are all working right when you pull the pin, the camper battery feeds 12-volt DC power to all four camper brakes at once. If you listen closely at the wheels, you can hear a slight hum most times, but not always. And sometimes you hear a click the instant the switch is pulled; then the low hum should start. The hum may change sound and come and go in volume. The camper battery DC power energizes an electric magnet in each wheel brake assembly that clamps onto the brake drum. As the camper tries to roll, the magnet arm attached to the brake plate and magnetically attached to the brake drum applies mechanical force with a lever (the magnet arm) to expand the brake shoes against the brake drum and stop/hold the camper. The camper has to roll a little before the brake shoes engage.

And yes, the camper battery is where the power comes from to energize the camper emergency brake system. It may/is technically be considered illegal to tow the camper without a working battery or breakaway system, as this critical safety feature will not work if the trailer is uncoupled from the tow vehicle going down the road. The emergency breakaway system is in the laws of most all states to have on trailers with brake systems and is Federal law also. Here is an excerpt from the Federal motor carrier mandates. See part d. https://www.govinfo.gov/content/pkg/...-sec393-44.pdf

Armed with this info, when you get time and want to know, pull the pin and listen. Then put the pin back in, do not leave it out a long time. It is good you had a new switch installed. The switch manufacturers state in their instructions to change the switch every 3 to 5 years, pending the brand. Water gets in and corrodes the switch, which does not work right then. This corrosion also creates high heat from electrical resistance, and often the switch burns up. For many campers/trailers, this switch is a forgotten safety feature, and the switch never gets changed or tested annually.

Ask for any clarifications on this if you need more.

John

PS, do not use this emergency breakaway switch as a parking brake for the camper. I have seen some good folks do this practice, not knowing the big problems that can come from doing this. Once explained, they stopped the practice. No one ever explained it to them, and they thought it worked like the parking brake on a car.

[JohnB]

Originally Posted by Tammy Lou

Thanks John!
No DC power to anything...water pump, radio, fringe light, etc.

As to the "master switch", I now believe what the seller was referring to was the wall switch, which (when I hook into shore power) only powers ceiling lights whose rocker switches are left in the on position. It is actually the second switch next to the door.
I've included a pic of the wall switches.
Great info about DC power loads and disconnecting the battery negative wire for storage...thanks. As a matter of fact, I did find the fridge climate control switch in the on position and turned it off before I got the new battery installed.

I haven't found anything looking like a switch near the battery. Including pics of what is there. I had the emergency break-away brake replaced before getting a new battery and included pics of that.

It looks like the fuse that I found blown is the camper power converter protection fuse as I believe it is blue nut-connected with the thicker red wire, although it is difficult to see. There are red wires going into two blue nuts. Including pics in the next post as I'm at max upload.

Of note is that prior to replacing the battery, I was at a campground when a big storm hit and the power went out. Of course the DC power (when off shore power) wasn't working before that, and I attributed that to a dead battery. Additionally, I heard a little spark sound today when hooking to shore power using a 30amp to 110 tail and a 3-prong extension cord at my home.

Originally Posted by Tammy Lou

Here are pics of the contents of the wooden box under the couch seat. There are three blue nut and three white nut connections. (Repeating previous post)...It looks like the fuse that I found blown is the camper power converter protection fuse as I believe it is blue nut-connected with the thicker red wire, although it is difficult to see. There are red wires going into two of three blue nut connections.

Tammy,

You have done well, and great pics! They really help. I'll try to address each issue.

1. The master switch, I agree with your explanation above. The wording master switch is misleading; Sunline gave us wall switches in most cases to control at least one light when you walk into a room. In your case, on the T1950, at the entry door, and the bathroom door. And yes, the fixture that the switch controls also have individual switches that have to be on in order for the light to work. At this point, and from your pics, there appears to be no battery disconnect switch or system.

2. The fuse that was blown in the wooden box (the 7-wire plug junction box); let's compare notes. From the great pics you posted, I could back into what fuse does what. I do not know which one you physically changed. See this pic; you look and tell me which fuse you replaced.


3. The spark crackle when you plug the camper into shore power at home; this can happen when the power converter powers up; it is drawing enough power to create that sound when you plug in. But we will keep this in mind as we sort this out.

4. You have no DC power at all in the camper when it is not plugged into shore power. OK, got it; now we know we will hone in on this topic.

Before I start down the wrong road regarding what might be the problem, confirm which fuse blew in the wooden junction box.

Also, check this, take the cover off the top of the battery case and confirm the heavy red wire is attached to the + Pos terminal and the white is connected to the - Neg terminal. If this is backward, it is a problem and can create some of these problems. If there is anything other than the two big wires under the battery cover, take pics and post.

The meters you posted are perfect for troubleshooting the camper. You may be using one of them soon.

I hope this helps,

John

[Tammy Lou]

John,
It was the one on the left - the truck charge fuse - that I found blown and replaced. I went ahead and replaced the other fuse as well at the time, even though that fuse didn't look blown.
I removed the battery cover and confirmed that the cables are hooked up correctly, red to + Pos and white to - Neg. Nothing else is under the battery cover.

I unplugged from shore power for safety as it seemed that the extension cord was getting too warm. Plus a wind was picking as a storm was coming through. All is quiet now but I'm leaving it unplugged overnight.

Thanks again for this awesome help!
Tammy

[Tammy Lou]

John, I took a closer look at all the pictures. I'm convinced it was actually the power converter fuse that I found blown. I'm comparing the orientation of the black tie down of green and white wires along with my initial picture of the blown fuse. Sorry, I was confused by the orientation of the phone/camera.

[JohnB]

Originally Posted by Tammy Lou

John, I took a closer look at all the pictures. I'm convinced it was actually the power converter fuse that I found blown. I'm comparing the orientation of the black tie down of green and white wires along with my initial picture of the blown fuse. Sorry, I was confused by the orientation of the phone/camera.

Hi Tammy,

OK, we will go with the power converter fuse that was blown. This might be easy or get more complex; let's try the more easy fix first.

Make sure the camper is not plugged in when doing this.

In your pic, there are two orange-colored fuses that say 40 amp on them; check each one that they are not blown. They are at the left of the long line of blue fuses


If one is blown, they are a reverse polarity protection fuses. Someone in the past may have connected the system backward, there is no little red LED's I believe, for these 2 fuses to show the fuse is blown.

I see you are on the forum, so you may see this before I get to the more complex post and can tell me if these are OK or not. I have to hunt for some pics of the WFCO 8955 all apart from a few of the campers I worked with that had them for the net response.

Be back soon

John

[JohnB]

Originally Posted by Tammy Lou

John,
It was the one on the left - the truck charge fuse - that I found blown and replaced. I went ahead and replaced the other fuse as well at the time, even though that fuse didn't look blown.
I removed the battery cover and confirmed that the cables are hooked up correctly, red to + Pos and white to - Neg. Nothing else is under the battery cover.

I unplugged from shore power for safety as it seemed that the extension cord was getting too warm. Plus a wind was picking as a storm was coming through. All is quiet now but I'm leaving it unplugged overnight.

Thanks again for this awesome help!
Tammy

To the extension cord getting warm, too warm is a concern. Good for you to have it unplugged until this is sorted out.

1. If you are at home and using one of the 30 amp (camper plug end) to 15 amp (normal home outlet end) RV cord plug adapters to plug into a normal-looking home outlet, they will work, but they also will limit the amount of power that can be on in the camper.

2. And there is an extension cord wire size and length concern to deal with, pending what you are using inside the camper.

3. Next up, the normal-looking outlet at the house; what else is on that power circuit that might be running while the camper shoreline cord is plugged in?

4. And lastly, what size circuit breaker is feeding the outlet? It might be a 15-amp or 20-amp breaker.

No. 2 & 3 above is what tricks most folks, followed by no. 4.

How long is the extension cord you are using? 25 ft, 50 ft, longer?

Look for wording imprinted on the extension cord's side and a number that calls out the AWG of the wire size. The AWG number is the amp rating the cord can carry. It might say, 16 awg (not good), 14 awg, better but still may be an issue, or 12 awg, good but length can be an issue. Which does yours have?

A. Now, inside the camper, the roof AC unit is almost a no go, to run on one of these power adapters unless you have, a full 20 amp circuit at the house with no other device running on it, the right length (short), right AWG size extension cord, and that the AC and the power convert are the only things on in the camper on electric. So, do not try and run the roof AC unit. The AC unit can draw 37 amps instantly, trying to start, then run at 13 amps once up and going; the starting problem is the issue.

B. The microwave is bad too; on high, it can pull a little over 13 to 15 amps and it pulses And no to the water heater on electric, it can pull 1400 watts or 12 amps on 120 volts.

A & B above pull more power than most times the adapter setup can handle, and that can create heat in the extension cord and the plug on the end. That combined with 2, 3, and 4 above.

But, running just the power converter and the fridge on electricity is doable if the no. 2, 3, and 4 above all checkout. Look over the list and see how yours adds up.

Power usage, extension cords, and even at the campground at full 30 amp power, is a common issue of running too much power all at once. This happens to almost everyone unless they stop and think or have someone explain it. The camper is not like the house at home.

At camp, I go by "only using one heat-producing device at a time". One AC unit, 1 toaster, 1 hair dryer, 1 water heater on electric, 1 portable electric heater, 1 microwave are the most common offenders, but there are others too. Every now and then, my wife or I forget, and the hot RV plug or tripped breaker reminds us. Suppose any 2 of the higher heat-producing item are on simultaneously. In that case, you can overpower the camper combined with the normal lower-level items that run all the time, like the power converter, a small coffee pot, a TV set, a small vacuum, etc.

Have a look and report back

I hope this helps

John

[Tammy Lou]

John, I pulled out the two 40amp reverse polarity fuses and they look normal and not blown.

[Tammy Lou]

I placed the two 40 amps back in and I have DC power!!! Maybe one was loose? Who knows, but I have power. Lights, fridge light, water pump all come on.

[JohnB]

Originally Posted by Tammy Lou

I placed the two 40 amps back in and I have DC power!!! Maybe one was loose? Who knows, but I have power. Lights, fridge light, water pump all come on.

YEH!!!!!

Glad we went with the simple fix first. I just finished getting all the pics ready for the more complex figure-it-out route, but they can be used in the future. I'll attach them just in case for learning at the end of this reply since you are not "into this"!

Yes, one of the fuses could have been loose in the socket, which would break the contact; it happens.

I have always said one learns more when things don't work right. Now you are armed with more info about your camper for the future.

Good job sorting this out; you provided good detail with pics, then more good pics and feedback along the way. Troubleshooting from a keyboard, we can only go on your words. Anything and everything you tell us helps, even if you do not know exactly why.

Now, have fun with the camper!

John

Pics for the future if needed.

WFCO 8955 from a 2007 T289SR- how to remove the front cover


What the power center looks like with the cover off


Close up on fuse board


WFCO 8955 wiring diagram


digital Volt/ohm meter (VOM) how to measure DC voltage


Battery state of charge voltage chart, lead acid battery at rest. (taken from Trojan battery site)

[Tammy Lou]

Thank you soooo much John! Great and useful info. I'll check into that extension cord info you provided when I return from my camping trip. The DC power was fixed just in time as my daughter and I are leaving today for a two-week trip from FL to IL!
Take care,
Tammy