no 12v power?

[WoodchucksOnWheels]

Hi all,
We just bought a 2009 Rockwood Freedom 1950 pop-up... planning on a cross-country trip later this summer and are very excited for it. We took a shake-down trip last week to get used to the rig, and on day 2 we lost 12V power to pretty much everything. For the most part we were plugged in to shore power, but as soon as we unplugged... nothing. I've combed this forum and have taken the first steps to troubleshoot... but I'm not sure what to try next. Here's what I've found (I'm new to electrical systems... so keep that in mind):

When plugged in to shore power, everything works fine (all lights, fridge, furnace, CO detector, etc). When unplugged from shore none of that works. I checked to see if the battery (new and working 2 weeks ago) is charged and properly grounded to the frame. According to my volt meter, I'm getting 13.5 V from the positive side of the battery to the frame. I THINK that means that my battery has power and is grounded (correct me if I'm wrong).

I've checked as many fuses as I have found... all look (visually) OK. The fusses I checked are the ones in the converter panel (including the reverse-polarity fuse) and the one near the battery. I've read talk about a resettable fuse on the trailer frame... I haven't found that. Does anyone know if the 1950 has one? Also, I know about the plunger-switch near the sink which cuts power when the sink is down, but I'm not sure how to test it... any suggestions?

Thanks in advance!

Jon

PS I'm also interested in getting a battery-minder both for my car (Toyota Highlander) and the camper... any advice there (either of the 'steer clear' or get this kind' variety)?

[SeaDog]

Welcome to the forum its a great place to get your questions answered. Hang in there I'm sure someone will have the info you are looking for

[soxgirl]

I have a 1950.... my son found an inline fuse coming off the battery behind and below the propane and battery. That one was blown for me

[jimmoore13]

I agree with soxgirl that this sounds as if it's the "breaker/fuse" that provides primary protection at the positive terminal of the battery.

Invest $10 to $20 and buy a VOM (volt-ohm meter), also known as a "multimeter." Use the "ohms" tester to see if you have a circuit through the "breaker," or just physically examine the fuse if you can see it. These are high amperage devices, so you may not be able to examine the fuse.

The VOM meter will tell you if you have "continuity" (a solid circuit) through the fuse/breaker. If you do, the problem is elsewhere. Meanwhile, the VOM meter will be helpful to test the state of your battery's charge, check other circuits, and so on.
There are many online tutorials on using a multimeter. This one seems pretty good.

https://www.youtube.com/watch?v=bF3OyQ3HwfU

ONE MORE OPTION. Many parts of a 12-volt (battery) circuit go through the chassis for ground. The ground wires are just screwed to the frame of the trailer...as with car lights. Check those wires and connections. Loosen the screw into the trailer frame and re-tighten it. If that fixes things, go back and do a better job cleaning up the terminals, frame connection point, and so on, then dab some grease over it to prevent corrosion.

[270S]

If you have 12Vdc power when plugged in, the converter is powering everything. If unplugged and no 12Vdc, somehow the battery bank is not providing the 12Vdc needed. The problem is the battery, wring, or fuses. Start at the beginning with a meter and follow 'til fault is found.

[WoodchucksOnWheels]

Thanks all for your responses and helpful advice... I did go get a multimeter and have begun to understand how it works. I also checked the wiring from the battery to where the lines go up onto the body. No re-settable breaker, but I did find an in-line fuse. 20 amps. I looks good (not broken) and when I test it for continuity with the VOM it beeps (good). Also checked voltage from battery positive (red) to the trailer frame and got 13.5 V. Does this mean my ground is OK? If so, I think my next thing to check is the kill switch by the sink (?) or the converter panel itself?

[WoodchucksOnWheels]

270S, thanks for the advice? Sorry to be dense but how do I 'follow 'til fault is found'? Do I use the continuity setting on the VOM?

[Flybob]

You say you are seeing 13.5v when measured at the battery. It sounds like this is with the converter on as a fully charged battery should be closer to 12.6V. Disconnect shore power and try checking the battery again. The good news is if you are seeing charging voltage at the battery the fuses and wiring are OK. Note that there are items in the unit ( ie CO/propane detector and Radio) that draw some current all the time. These items can drain a battery in a week or two unless the battery is disconnected during storage. The other option is to keep it connected to shore power. If you do this, check the water level every month or so.

[Scrapper]

Have the PUP plugged in and turn on the light and lift the sink up as though you are going to close up the camper to test the plunger switch at the sink. If it is working it will kill the light. I remember this from when we had a PUP from '97 to 2000.

[WoodchucksOnWheels]

Thanks flybob and scrapper. The lights do work when plugged in to shore power, and the go off when the sink is lifted... so I guess it isn't the sink kill switch. Flybob, I THINK I tested the battery voltage while unplugged from shore power, but I'll try again. Is there a good way with the VOM to make sure that the ground connection to the frame is good? Continuity between negative and frame?

[Scrapper]

To test continuity connect the VOM between your positive on the battery and any clean spot on your frame using the voltage function of the meter. You should get 12+ volts.
If you want to test the ground connections using the OHM or continuity setting then you should disconnect the positive from your battery or you could damage the meter.

[Flybob]

I would check the battery first.

[WoodchucksOnWheels]

Scrapper, good to know! Hope it isn't too late for my VOM... testing voltage between Pos and Neg posts of the battery itself, I get 12.8 V whether or not I'm plugged in to shore power... interpretation? I'm guessing it means that the battery is either fully charged or not connected at all to converter... I'm guessing the second option.

[Flybob]

12.8V ( whether plugged in or not) sounds like a charged battery that has not stabilized yet. Check on the under side of tongue of the pup and look for a resettable breaker ( see photo). There should be a small button on one end that will reset it.

[jimmoore13]

Lots of good advice from others in this thread.

Many of these comments are predicated on the belief that you tested your battery while connected to shore power and got a reading of 13.5 volts. If you were NOT connected to shore power and got that reading, the breaker serving the battery from the converter may simply need to be reset.

Many converters have some breakers and some have fuses. Often, the fuses are for the "loads" like lights, etc. For giggles, check the all the breakers by "cycling" them off then on again. Many breakers may fool you when they trip. They seem to be "on", and if you move them toward the on position, they don't do anything. A tripped breaker must first be turned all the way off, and then turned on to reset it.

Consider: the converter - central power unit in the camper - both accepts power from the battery when the shore power is disconnected - about 30 amps - AND sends charging power to the battery when the shore power is connected. Somewhere on your panel inside the camper should be a breaker or a fuse that manages that primary signal to and from the battery. Unless you have an electric winch hoist for a PUP, there is probably only one red wire to/from the battery, so it's very likely that only one breaker/fuse is between the converter and battery. I'd bank on a breaker doing this job.

Again, you checked the voltage between the positive terminal and the frame...great idea...and you got 13.5 volts. As your intuition suggests, it does not seem that you have a ground problem at the battery end -- but the ground problem could be between the converter or power panel and chassis ground. That's unlikely, but don't rule it out entirely.

Again, and as Flybob suggests, it sounds as if you were connected to shore power. 13.6 volts is the rated "charging" voltage from most converters. 0.1 volt difference in measurement is within the tolerance limits of a cheap meter. The fact that the battery is being charged by the converter may rule out a fuse or breaker. But if you weren't plugged into shore power, a breaker or bad ground at the converter/panel end is still a possibility.

Try disconnecting the battery entirely. Remove the red and black wires. Check the voltage. If your battery is accepting a charge, it should be around 12 volts or more. If it comes up quite a bit less, the battery may be bad.
Batteries die strangely. They often develop internal shorts, and instead of 6 x 2-volt cells, you end up with fewer active cells and the possibility that the battery won't put out any voltage at all. This can happen suddenly...and it's often a result of heat...not cold. But it can also be the fault of poor battery maintenance. That dead battery will still serve its role when connected to shore power, and you won't know it's dead.

Pop the caps and be sure the plates are flooded with water. If the plates (this will make sense as soon as you look) are exposed with too little water, the battery can be ruined in short order. Charging a battery with too little water in it causes a problem called sulfating. You MIGHT be able to save it, but probably not: https://patch.com/maryland/elkridge/...d-acid-battery

By now, you may be wise to pray for a bad battery, because from here things may get really difficult. And a lot depends on whether you were connected to shore power when you tested the battery and got 13.5 volts.

Now it begins to get more complex. Thoughts:

• Your breaker panel is held in with a few screws. UNPLUG FROM SHORE POWER AND DISCONNECT THE BATTERY. Then remove the panel.
• Look for the obvious: loose wires, or loose screws holding the wires. The "positive" (red) connections go to various spots to connect to fuses or breakers. Double-check each connector to verify that the screw is tight and the wire is seated properly.
  In most cases, all the "negative" (black) connections go to a common buss bar. One chunk of metal with lots of screw spigots in it. Check them all.
  And look for a loose wire...disconnected and reconnect it.
• Find the chassis ground wire from the panel or converter and trace it to where it's connected to the chassis. This is a real long shot, because your lights, water pump, fan, etc. (all 12 volt devices) worked. But all of them MAY be two-wire hookups...with a positive and negative that go back to the panel. If (and only if) the battery uses chassis ground and the rest of the 12 loads use 2-wire connections to the main panel, you just might get lucky and find a bad chassis ground going from the converter or panel to the trailer frame.

The puzzling part is that the battery appears to be charging when connected to shore power. And that rules out the breaker, chassis ground, and all the other guesswork.


In that case, you might get lucky, but I'd begin to have my fingers crossed for a trashed battery. It's $100 or so for a new one, but it would solve the problem easily.



Best of luck. You may end up as quite the electrical expert by the time you figure this out.

[Scrapper]

Originally Posted by Scrapper

If you want to test the ground connections using the OHM or continuity setting then you should disconnect the positive from your battery or you could damage the meter.

The reason I say this is the meter has it's own battery inside, either 6 or 9 volts, which it uses for ohms. The continuity setting uses the same circuits as ohms but also adds a tone generator and speaker. When you do the test you are adding in the 12+ volts to bring the total voltage to 18 or 21 volts. This could damage the circuitry in cheaper VOM's.

[270S]

Originally Posted by WoodchucksOnWheels

270S, thanks for the advice? Sorry to be dense but how do I 'follow 'til fault is found'? Do I use the continuity setting on the VOM?

Continuity tests for open circuits. To be safe at your level, limit it for fuses (unpowered) for now.

Turn 120Vac power off to vehicle (unplug) that turns off converter power. Place the meter in Vdc mode with apx a 20 V range setting. Put the meter's red positive lead on the battery, then the black negative lead on the frame. If the battery is new & charged, you should read between 12.8-13.2 Vdc. then go to the next item - place the red lead on th epositive input side and the black lead on the frame, .... continue down until the voltage goes to zero. At that point you know you have an open/broken circuit between there and the last point you tested good.

[jimmoore13]

P.S. All of that may sound a bit daunting, but it's just basic electricity - not electronics. Don't do anything that makes you concerned for your safety or the safety of your gear, but based on your intuition with the VOM meter, I suspect you have the skills to figure it out. And there's always a dealer option.

[WoodchucksOnWheels]

... a very long time later (apologies)...
So, it turns out that it was a blown fuse… It just didn't LOOK blown. I traced the circuit all the way back to the panel and then users the continuity tester to check the fuses... bingo!
Thanks to all who helped problem-solve!