Univolt Operation

[melprice]

Am I correct in thinking that when hooked up to shore power my univolt should run the 12v systems i.e. lights and water pump as well as any power left over going to charge the battery?

Here is my situation. The univolt is humming. It seems to be charging the battery but it is not running the lights or water pump.

Anyone have an idea what is wrong.

[BobbyW]

When you disconnect from shore power, do the lights and pump then work?

-BobbyWright

[83Excella]

How about a fuse or circuit breaker blown/tripped?

John

[FrankR]

It has been my experience in trouble checking......the ground did it. Airstream usually fuses the grounds for some reason that eludes me and rational. While chasing any non-functioning apparatus, check all the easy stuff first. Make a can od WD40 your best friend. If ya spray everything, something may work and no harm will be done. I eliminate any fused grounds. A 12 volt test lite should be mandantory with the ownership of an Airstream......

[melprice]

Sorry guys, I could have been a little clearer here.

Whether I have shore power or not the lights and pump work but, the battery voltage is so low that turning on a 2nd light dims the first. That's how I know the univolt isn't running the 12v system, even with shore power I can't turn 2 lights on at the same time without the second one significantly dimming the first.

After a few hours the battery voltage is up again so I know the Univolt is charging it. The battery is on it's way out, I know that but from what I've read in the forum the Univolt should run my 12v system even without a battery connected shouldn't it?

Frank, I'm not sure I understand about the WD 40, does this help make connections when they are maybe dirty or corroded. Where would I spray, inside the front cover where all the fuses are? Would I acheive the same or better results by taking out the fuses and cleaning all the contacts?

Are all the fuses in and around the Univolt, none lurking elsewhere I miss?

[FrankR]

WD40 will drive out moisture and disolve any corrosion....say electrolysis. This is an action where as two dissimilar metals react to each other. Some metals are active and others are passive. Bet you wanted to know that>>>>.hahaha

OK, from the beginning....Disconnect the battery or batteries and isolate the positive cable. Isolate.....wrap with nonconductive material so as to not allow any passing of electrons.....
Check to see is anything works...Connect to shore power. Converter should hummmmmmmmm..
Use multimeter on volt scale to measure converter volt output..... Should be about 14volts. Spray every wire end, connection and fuse. Turn each fuse at least 1/2 turn at it's location. Measure or test every fuse on each end to find any/all voltage. Check to see what works and what does not work......All fuses are at same location........near converter. Look at converter and learn max amps output as in 30, 40, 070, or ???

[thenewkid64]

Not to contradict Frank, but with the older univolts running them with out a load can lead to their demise. If the coach battery is weak, I would recommend connecting any kind, even a good ole car battery before testing everything as Frank described.

I have had fuse panels fail due to age and heat, so check it all....

Good luck

[83Excella]

Sounds like your battery is too far gone already, I'd replace the battery asap for fear of risking ruining the univolt. Do not run your electric without a battery installed you must have at least a charger connected or the univolt will be kaput.

John

[melprice]

Thanks for all of the advice. I will get a new battery then go through the checks suggested by Frank.

[83Excella]

Do this check to see if your univolt is working;

With the Uni-volt off, measure the voltage at the battery. It should be 13.8V +/- 1V. Turn the converter on - the measured voltage should increase by about 0.5V.

John

[melprice]

I have tried the voltage check and I'm getting nothing. What could be wrong? Are there any user replaceable parts after I've sprayed with WD40 and turned/checked all the fuses?

[Action]

I read that running the (univolt)system with out a battery will damage the univolt.

So let me be clear with the Q. --- I currently do NOT have a battery installed. (Long story on that issue) And I have used my trailer for one long weekend plugged in to 110. (That's the point isn't it? To use it!) And there have been many occasions that I have plugged in my trailer to run the A/C, use the lites, and/or play the 8-track. (OK I don't have any 8-track tapes but I listen to the FM) ~~~~~~ So am I causing damage to the univolt system?

Second Q. How do I know that I have a univolt system? There is a box with lots of wires going in and out in the back of my trailer. The box is loose, not screwed down and it does not say univolt on the box. (Yes, Frank, I know the installation needs work. It is no where near as sanitary as your work.)

Frankly the electrical system works very well so I have not addressed anything in that system cause there are other pressing issues in my "bullet". However, I don't want to add to any of the other issues that I have in my "bullet" by plugging into 110 and causing damage. ~ Note I have a 1966 unit, and if there was a shop manual I would have bought it by now.

>>>>>>>>>>>Action