12V partially working

[mysilverbullet]

Hello all,
Last I knew I had 12v lights when 120v was disconnected. Now, the water pump works, but nothing else. All 3 fuses continuity tested to be working. Not familiar with the contacts at the bottom and if something there blew, or if the converter might have crapped out? Any ideas? Thanks! Greg

[mysilverbullet]

Photo of 12v electrical panel

[TG Twinkie]

The devices at the bottom are circuit breakers. You should be able to check the output of each with a meter of test probe?
If the pump runs. You have 12 volts either from the battery or converter or both.

[mysilverbullet]

Thank you again! Is there a manner to re-set these? I tested incoming FUSES with voltmeter and got 12.66, have continuity between each fuse and breaker. 12v lights all work with 115v. If converter died, wouldn't that stop converting power to these lights? Sorry, I know basics, but 'm not too savvy at some of these things. Thanks again!

[DKB_SATX]

Originally Posted by mysilverbullet

Thank you again! Is there a manner to re-set these? I tested incoming FUSES with voltmeter and got 12.66, have continuity between each fuse and breaker. 12v lights all work with 115v. If converter died, wouldn't that stop converting power to these lights? Sorry, I know basics, but 'm not too savvy at some of these things. Thanks again!

So, you're saying that 12V stuff works when you're plugged into shore power (i.e. the converter-charger is working) but not when you're on battery power, but you're seeing 12.6v coming from the battery to the fuses? Or the 12.6v is when the converter is running (which would be a low value from a converter)?

If you know the battery is good (puts out 12.6v under light load, such as a 12v test light across the terminals for example) then you start tracing connections. Make sure you have good connectivity to to the terminal block (there might be an open fuse between the battery and the terminal block, for example.)

The 12v breakers are self-resetting and they either work or they don't, there's nothing to reset.

Remember that lots of stuff uses common ground, so you'll have one "hot" wire running to the lights and they rely on the structure of the trailer to complete the circuit as the "ground." It might be that you have some weird difference in grounding between the converter and the battery... the chassis of the converter being grounded but not passing the connection from the battery to ground, etc. (I'm just fishing here, troubleshooting ancient 12v is an iterative process of elimination.) Good luck!

[TG Twinkie]

Unless you have a good battery that is supplying the 12 volts. The converter is working.
If the lights are working. What doesn't work? You say the pump works.
The breakers are self resetting. Use your meter and check the right side of each breaker. There should be 12 volts on each one.

[mysilverbullet]

When 115v is disconnected, I have power only to the 12v water pump, nothing else works. When connected to 115v, everything works, all 12v lights and 115v outlets etc. The battery showed 12.6 volts at did the incoming fuse, plugged back in and now at 13.94v. There is continuity across breakers, and I tested the hot side of each breaker and used nuetral bar for ground. The bottom breaker shows 13.94 volts but other two only show 7.56 volts. If this is correct way to test, looks like they're the problem. Where do I find such antique parts, can't imagine the local trailer supply or home depot has? Thanks again!

[Al and Missy]

All of the lugs on the fuses look to be corroded and the one in the middle on top looks burned. I’d suggest disconnecting shore power and batteries and then removing (one at a time) and cleaning all lugs with a wire brush, reassembling and testing again. If that middle top lug is burned, replace it.

Al

[TG Twinkie]

Do you have 12 volts one the red wire feeding the top two breakers?
How about the blue wire feeding the bottom breaker?

[mysilverbullet]

Nope, only 13.94v at blue wire bottom breaker, other two only 7.56. Yes, I agree everything's pretty corroded so will unplug everything and clean up all connections. Thanks again!

[TG Twinkie]

The first thing I would do is replace the fuse in the red wire. Making sure it has good tight contact with the fuse holder on both ends.

[TouringDan]

It doesn’t make much sense that the water pump works when you have either battery or shore power but the lights only work when you have shore power, ie. the converter is providing the 12v power.

My only suggestion is to replace the 12v panel with a simple Blue Sea panel. I did this on my 66 Tradewind before I had 12v power problems because I could not understand how it, the original, was wired. See post number 216 of my thread Dan’s 66 Tradewind Improvements in the trailer section.

Dan

[mysilverbullet]

I cleaned every connection, tested outgoing side of each breaker to neutral and got 12.75 volts everywhere but interior lights still do not work. Are there 12v breakers located in the interior anywhere or inside the Univolt? Thanks again!

[TG Twinkie]

Originally Posted by mysilverbullet

Nope, only 13.94v at blue wire bottom breaker, other two only 7.56. Yes, I agree everything's pretty corroded so will unplug everything and clean up all connections. Thanks again!

In post 4 you said the lights work.????????

[mysilverbullet]

Only when 115v is plugged in, not on battery only.

[TG Twinkie]

Originally Posted by mysilverbullet

Only when 115v is plugged in, not on battery only.

Do you have 12 volts when not plugged in?
Battery voltage?
Voltage at fuse panel on battery only?
Battery connections clean and tight?

[mysilverbullet]

When plugged in, it went from about 12.7 to nearly 14 volts. (Battery, 1st fuse connection and bottom breaker all the same). I checked Univolt and all fuses good. I replaced all 3 glass fuses and 2 of the 3 breakers and still nothing. Thought I figured it out as the pump switch has 2 hot lines incoming which, if factory did was shoddy at best. Took apart, cleaned and wired properly with a pigtail, but still nothing. The voltage this morning tested good on the other 2 breakers, then this afternoon, nothing. Replaced, now shows 6.6 volts. I'm at a loss as to what could even be doing such a thing.

[mysilverbullet]

Actually, only shows 6.6v when plugged into 115v, only millivolts when unplugged now. I replaced water pump few days ago, but only 2 wires coming in, nothing going elsewhere and pump works perfect. Other than that, only thing I've done is pick up the bundle of wires going into the Univolt to see if there was an unused circuit there for new water heater, which all wires appear to be in perfect condition. Maybe something's loose inside Univolt? Are all 3 breakers supposed to show 12 volts? The top two are joined together with a plate, so maybe the 6.6 volts doubled is right? Anyway, thanks again!

[TG Twinkie]

All 3 breakers should read 12+ volts both on the left and right side.
12 volts on the left is power to and 12 volts on the right means the breakers are not tripped.
Do you have 12 volts on the blue wire?
Sounds like a voltage drop problem. But makes no sense if all works when plugged in.
There must be a bad connection between the battery and the fuse panel.
You do have a 12 volt battery installed?
Or did you install 2 6 volt batteries?

[TG Twinkie]

14 volts means the converter is working.