interior lights not working off battery power

[GoodoleBob]

Just back from a trip. I unloaded stuff and once the fridge was empty I disconnected shore power leaving just the battery connected. Well I noticed my interior lights are not working now. I checked battery...getting 13 volts there. I checked the 30 amp fuse in the red lead which is mounted in a box outside on the front frame rail...fuse was fine..checked it by eye and by continuity tester. Check my interior panel for a possible breaker trip...all were normal. There are several fuses in there as well, but labeled for other functions not lighting. I traced the red lead which runs down the port side frame rail and disappears into the darkness so I presume there is no reason to believe that lead has been comprimised and why would there be a fuse in such an unlikely location...ok that's as far as I have gone before writing about the situation here so my old Sunline buddies can help me get it fixed.

Thanks for your time.

[bunjin]

Hi GoodoleBob,

I'm not a electrician by any means. Did you check ground? You imply "all" interior lights not working.

[Gene]

Just to make sure I understand:
The 12 volt lights work on shore power but not on battery.
Battery is good (13 volts)
Fuse at the front frame rail is good.

Does anything work on 12 volts? i.e. water pump, heater fan, stove fan, monitor panel lights .... stuff ....

Inside the converter where the 12 volt fuses are located there is are two 30 amp fuses, are they good?

Good point on the ground. If the battery post ground connection or the other end of that cable where it goes to the trailer frame is not good then the converter could provide 12 volts but nothing would work on battery because the ground side is not conducting. Try measuring from the hot battery lead to somewhere on the frame.

Try plugging the 7 pin into the tow vehicle and see if the lights work. That path uses the tow vehicle battery and ground through the 7 pin connector.

[Gene]

Originally Posted by GoodoleBob

.... and why would there be a fuse in such an unlikely location.....

The fuse or resettable breaker close to the battery protects against a major short circuit in that battery line.

[JohnB]

Hi Bob,

Today may be your lucky day... We just happen to have a wiring diagram for a T2499... Our one and only wiring diagram... It is from my 2004 unit however yours should be real close.

Sunline Coach Owner's Club - Sunline Owner's Files - Sunline Solaris T-2499 Wiring Diagram

Reading the DC wiring diagram on page 2, the lights are split up on 3 different circuits.

Try this and see if "any" work. This adds to where Gene is having you check.

Circuit 3 = try the cieling light in the bed room
Circuit 4 = try the light over the sink. Also the fridge light was on this and you said you emptied the fridge and should of noticed if the light was on or not.
Circuit 5 = try one of the spot lights on the rear wall in front of the big back window.

Do any of them work?

Also jog the water pump, does it run?

Also just try the furnace?

Trying to figure out if you lost "all" inside 12 volts or a portion of it.

Do the lights or anything else work on shore power?

Knowing the answers to those questions helps narrow down the hunt. The 12 VDC power distribution system is the same for the battery as it is for the converter. The thing that changes is what power source feeds the 12 VDC fuse bank.

If the converter works the everything in the camper but the battery works nothing, this points to:

- The self resetting breaker out on the A frame died. Kitty had one corrode out on her.
- One or both of the green 30 amp fuses inside the camper in the fuse bank are loose or blown.
- The hot wire from the battery to the power converter has issues. (not likely, but not impossible)
- You lost ground between the battery and the camper frame. Odds are low but again not impossible

If you fell comfortable doing this, I would start with checking the lights and other 12 VDC devices in the camper. If everything is dead, I would start with the volt meter in the convertor panel on the big red and big wire wire looking for 12 volts. If that is dead, then go to the A frame box and sort out where you are loosing the 12 volts. If the battery has 13 volts, well it is not making it inside.

BTW the 30 amp fuse on the A frame is for the charge line to the truck battery. There is a self resetting circuit breaker in the box on the A frame that feeds the converter. Making an "assumption" your 2007 is the same as my 2004 was, here is what is inside that box. Does this look like yours?





Good luck and hope this helps

John

PS After thinking about Gene's thought, if you plug the 7 wire in the truck and the truck running and the camper lights run off the truck, then this points to the self resetting circuit breaker or even more odd, the disconnect switch. A volt check on the circuit break on the A frame will tell for sure. Just unhook the truck when testing.

[GoodoleBob]

Wow great response my friends! I did try the light over the sink, the light in the galley nearest the fridge, the range hood light, the bedroom ceiling light, the living room light controlled by that switch just inside the doorway, the outside light over the hitch....all nothing!

I did have the ability to hear the radio if that provides any clues!

Yes John my black box is essentially the same as your photo show.

Yes Gene they worked when I was still connected to shore power.
Tonight I will re-apply myself to the various suggestions made, and see what I can discover. Note, electrical is my least comfortable subject. Talk real basic to me…or I will be lost. For example when you say “Try measuring from the hot battery lead to somewhere on the frame” Exactly what am I testing here? Using my cheapie multimeter set on what…DC voltage, continuity…really need ultra basic explanations if possible please.


...and as always thank you for taking the time to help me.

[mainah]

What model # is your converter/charger system?

[PTHutch]

Originally Posted by GoodoleBob

I did have the ability to hear the radio if that provides any clues!

Bob,

If your radio is working from only the Battery, that indicates you did not lose all 12V and then to me it indicates it's not the battery ground or any wire leading up to the power distribution center, but possibly a circuit(s).


If no fuses are blown, I would pull off the face plate of the power distribution center and make sure all wires are securely connected. If you have a battery kill switch, to be safe, turn the switch to off before removing the face place and checking wire connections.

If it's a circuit, I would expect the lights wouldn't work on shore power either.
Have you plugged back into shore power to confirm the lights do work when plugged into shore power.

If they work on shore power and not from battery - then I'll defer to JohnB for his troubleshooting expertise.

Hope this helps.

[GoodoleBob]

Ok back with an update.

Plugged in 7 pos hitch connection on my truck...all lights etc work fine.

Plugged in shore power...all worked fine also.

Opened up the black box on the front frame member, voltage check across the circuit breaker connections showed very weak current flow...like .1-.3 at best. Cheap multimeter does not breed much confidence, but still there was little current flow.

I took that circuit breaker out, and will replace it....anyone able to specify the particulars on that C/B...the data on mine is so illegible as to be useless. The brand name was Shorkito if that helps.

Now if that does not cure the problem what's next?

More comment welcomed.


Thank you in advance.

[mainah]

It most likely is 35 amp any auto parts store will have them.

[mainah]

If it worked hooked to your TV and it works plugged in you might want to start some where near the battery dirty cables? Bad connections?

[GoodoleBob]

Under magnification I can read partial data on that CB, I think it goes 12V N25 7

Battery connections are clean and tight (wingnuts), but that was a good thought.

[Gene]

Hearing the radio while the lights don't work while on battery is a head scratcher.

Originally Posted by GoodoleBob

..., voltage check across the circuit breaker connections showed very weak current flow...like .1-.3 at best. .....

Using John's picture:


if the circuit breaker is good your meter, set to measure DC volts, should measure zero volts with one test probe on each of the posts in the picture above. Think of that breaker as an on/off switch in the ON position.

If you set the meter to measure DC volts, you should measure 12 volts from any metal part of the trailer (ground) to either or both of those posts on the breaker in the picture. You should see the same voltage on both posts with the other meter probe connected to some metal on the trailer frame (ground).

“Try measuring from the hot battery lead to somewhere on the frame” - translation, with the meter set to measure DC volts connect one meter probe to ground and the other to the + (plus) lead on the battery.

[GoodoleBob]

Hi Gene...so your saying the way I measured with a probe on each of those threaded studs of the CB and my meter set on DV volts I should have gotten a zero reading? What about getting the .1-.3 which I noted above? Is that not essentially zero in this situation? Now I am not sure if that breaker is needing replacement at all.

What will measuring DC volts from trailer frame to either CB stud tell me if it verifies 12 Volts?

I'm afraid I still do not see a clear path to fixing this problem.

Did my using the truck battery through the 7 position plug to ensure the lights worked mean anything?

[mainah]

I would say yes it points to lack of power from your camper battery. If you have 13 volts at the battery that is more then enough to light your lights so you'll need to follow the lead from the battery and find out where your power disappears. If the breaker has 13 volts on one side and not the other the breaker is toes up.

[GoodoleBob]

New breaker solved the problem finally. I appreciate everyones assistance.

Thanks Folks

[Poppy & Nana]

Glad to hear all is well!

[Gene]

Good to hear it is solved Bob. See, all that electrical stuff isn't all that hard after all.

[JohnB]

Hi Bob,

SOC comes to the rescue once again!

Sorry.... been out and about but I see you made it through and did good!!!

The only thing that makes no sense is the radio working and no lights.... This was the radio that came with the camper correct? And not another battery operated one you added?


John

[GoodoleBob]

Hi John,

Yes the oiginal radio from Sunline. I noticed it being lit up so on a whim I pushed the on/off button and music played. I turned it off and made a mental note to mention it here in case it had any diagnostic worth. I truly do not understand the ins and outs of the trailers electrical operation beyond very basic things. Is there any capacitance stored in that radio which might have allowed it to function for a brief moment for my test?