No 12-Volt Power

[Silver Threads]

We decided to take a short camping trip this weekend. While we were there, yesterday actually, I was watching TV. The air conditioner was running, and John decided to make coffee, nothing we hadn't done the day before. The breaker at the camp site kicked off. When this happened, the kichen light kicked on. Then a few minutes later, it went off. Flipped the breaker back on, no problem, at least that we knew of. Today when we unhooked everything to get ready to come home, we have no 12 volt power. We checked all the breakers and fuses and they all look fine. Are there any fuses hidden somewhere we may not know about? All the ones we have found are inside the univolt.

[moosetags]

I am not familiar with the older Inivolts, but we had a similar problem with Lucy. We lost a portion of our 12 volt system while messing around with the interior lights. I looked at all the fuses, and they all looked good. Out of frustration, I alligator clipped each 12 volt circuit in turn and founs a 20 amp fuse that was broken. It did not look burned, nor did the citcuit appear to be separated. Upon very close examination, the conductor in the fuse had in fact severed.

[azflycaster]

Do you have 12 volts when connected to shore power? I will guess so, because you did not know it untill you got home. You can not get any power from the battery? All the fuses on my 75 are on the 12 volt power panel except for the battery (-) fuse which is on the floor in front of the panel, hidden under a piece of carpet.

[Silver Threads]

Thanks, we will check all the fuses again and look to see if there is another one hidden.

[overlander63]

Tammy, it could simply be a dirty battery cable end. The Univolt was supplying power to the 12 volt stuff while it was plugged in, and when you unplugged it, away went the power. The load of several lights caused the battery to lose connection. So, check the battery cable ends and connections to the battery before going crazy looking everywhere else.

[Silver Threads]

Thanks Terry, we will check them!

[john hd]

tammy

look at the negative cable just outside the univolt. there is a 50 amp glass fuse on the negative cable.

it is mounted on a black bakelite board about 1 by 2 inches long, sometimes they are hard to spot.

check that one and report back!

john

[Ganglin]

My guess would be the fuse at the battery, as mentioned above.

[Silver Threads]

Back again, checked the fuses, all of them, battery cable ends, and still no power without being plugged in. Any more ideas or suggestions? Thanks for your help! We really do appreciate it.
Tammy and John

[Foureagles]

T & J:

If y'all have 12 volts on shore power, then the Univolt is doing it's job, at least as far as distributing power to the working circuits. If disconnecting from 110 causes 12v to fail, then either your battery has gone T.U., some connection is broken, and/or the Univolt is not putting out enough juice to charge the battery. I find that those ol' blue boxes generally charge (if not overcharge) the battery even when too feeble to do much else. If, when hooked to 110 and all connections are verified good, turning on every 12v load causes goofy behavior like dimming lights or intermittant function, then it's probably time to invest in a new converter. But charge the battery first, and see if things change as/if it runs down.

[john hd]

any voltage at the battery?

by "checking" the fuses what exactly do you mean?

john

[Anon]

Originally Posted by moosetags

Out of frustration, I alligator clipped each 12 volt circuit in turn and founs a 20 amp fuse that was broken. It did not look burned, nor did the citcuit appear to be separated. Upon very close examination, the conductor in the fuse had in fact severed.

ALWAYS carry a cheap little digital multi-meter with you. At the very least, carry a continuity checker.
A fuse can open at the base and you would never see it. Check it for continuity with a meter and you will know for sure.
I like the multi-meter because it can be used for so much more then checking continuity.
They cost $10-20 for the cheap ones at Radio Shack, Lowe's or Home Depot.

[overlander63]

Originally Posted by pattersontoo

ALWAYS carry a cheap little digital multi-meter with you. At the very least, carry a continuity checker.
A fuse can open at the base and you would never see it. Check it for continuity with a meter and you will know for sure.
I like the multi-meter because it can be used for so much more then checking continuity.
They cost $10-20 for the cheap ones at Radio Shack, Lowe's or Home Depot.

That, and a cheap test light.

[Silver Threads]

Thanks for all the input. "Checking" the fuses, guess its a southern thang, means we were inspecting them to see if they were blown. We dont have one the meter's to check them with, but is definately on the list of things to buy(does this list ever end..?). But on further inspection, we found that 2 of the 20 amp fuses were blown, near the end and wasnt noticed upon the first inspection, Thanks Brian. The battery is not totally dead, but very close. We bought it a couple months back and hadn't had any prior problems. John is charging the battery and replacing the fuses, and I will let you know how it goes.

[Silver Threads]

Ok, back again. Didnt help to change the fuses and charge the battery. Still no power on the 12-volt. Any more ideas?
Thanks
Tammy

[azflycaster]

My 75 TW battery has a plug in the cable so that you can remove the battery without unhooking the cables from the battery. It is located inside the battery area and can cause the problem you discribe. Try disconnecting the cable and connecting it again. Sometimes the connection gets dirty / loose.

If that does not fix it, you will need to meter the voltage from the battery to the 12 volt dostibution panel. You can get a meter at Home Depot for under $20. Everyone should have at least one of these.

[pmclemore]

I had a problem similar to this - turns out I had a loose connection at the 12-v block going from the batt to the battery isolator switch. If you feel the 12-volt connections, one or more may be very hot. Tighten the nut and reset the disconnect and you may get lucky.

Pat

[Silver Threads]

Thanks Richard. He tried unplugging and replugging. I guess its a trip to Lowes now! Will update shortly!!

[Silver Threads]

Ok, checked all the fuses and replaced the two that were bad. We bought this battery on 7 April and had assumed that it was not the problem. Been raining here and just now got out to check it, and it is dead. I believe it is shot as my charger will not charge it.

We had the camper plugged up here for quite some time since we got the new battery. Could it have been overcharged and ruined from being plugged up too long?

According to the manual, the univolt shuts down when the battery is fully charged????

I feel rather stupid for not checking the battery sooner!

[azflycaster]

If your UniVolt is the original unit I would say yes. They can over cookthe battery. One sign of this would be if the cells are low on water.