Master Switch Question

[Tartimisi]

This might sound like a stupid question but if y'all could advise us please. We were told that the master switch was to remain in the off position until we want to use the battery. The manual cautions this: Plugging the trailer into 120 volt city power with the master switch off will blow radio fuses and may damage other 12 volt components. The master switch is meant to be used when storing the vehicle.

Thanks for teaching us rookies how it's done

[Tartimisi]

I didn't get any advice. I'm going to try to reword my question. Is the master switch suppose to stay on the whole time until it stored and winterized for the year? When we are on a trip, it never is turned to the off position. It that correct?

[2005 ford]

I have a 1990 Excella and leave the master switch on when camping. If the rig is staying parked and not used I turn the switch off to isolate the batteries. When the trailer is winterize I pull the batteries and store them in a heated space and keep the charge up. I'll check my manual in the morning to see if I have the same warning about plugging into 110V. I was always under the impression that the switch isolated the batteries.

Bill

[Tartimisi]

Thanks for the reply bill. Do you leave the switch in the on position when your driving ?

[2005 ford]

Yes, I have a 3-way fridge and it runs off the 12V when traveling. Our switch is located behind the front gaucho and usually has stuff burying the switch so I don't turn it off at all if I'm using the trailer.

[Tartimisi]

Thanks again. We will start leaving it on The reason I questioned it was the statement in the owners manual. We have always left the switch in the off position and never had any blown fuses. But.... We know better now. Thanks.

[SteveSueMac]

Originally Posted by Tartimisi

Thanks again. We will start leaving it on The reason I questioned it was the statement in the owners manual. We have always left the switch in the off position and never had any blown fuses. But.... We know better now. Thanks.

Hi Tartimisi - what trailer/year and what page in the manual? I searched my manual for the words "master switch" and it wasn't in the manual. I searched for the word "store" (my disconnect has two positions: use and store). Got lots of results. The meaningful ones are included below:

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When the switch is turned “use” (on) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will receive power from the converter G and the batteries will be charged through the converter charging system.

When the switch is turned to “store” (off) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will still receive power from the converter, but the batteries are disconnected from the system. The batteries will not be drained with the switch in the store position. The converter will not charge the batteries with the switch in this position.
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No warning about tripping fuses there. But if your manual uses different language, I would recommend following your manual that accompanies your specific trailer.

[Tartimisi]

Originally Posted by SteveSueMac

Hi Tartimisi - what trailer/year and what page in the manual? I searched my manual for the words "master switch" and it wasn't in the manual. I searched for the word "store" (my disconnect has two positions: use and store). Got lots of results. The meaningful ones are included below:

----------
When the switch is turned “use” (on) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will receive power from the converter G and the batteries will be charged through the converter charging system.

When the switch is turned to “store” (off) and the trailer is plugged into a 110-volt shoreline, the 12-volt distribution panel will still receive power from the converter, but the batteries are disconnected from the system. The batteries will not be drained with the switch in the store position. The converter will not charge the batteries with the switch in this position.
------------

No warning about tripping fuses there. But if your manual uses different language, I would recommend following your manual that accompanies your specific trailer.

Hey. I have the 1984 Airstream Trailer Service Manual It is in section H. Electrical. It is on page H-3.

It's under the univolt interior electrical system

i could take a pic of it. But I'm not sure how to attach a pic to my message.

[n2916s]

I leave mine on (1986 Sovereign) pretty much all the time, unless it is in storage.

I run my reefer on propane while driving and the circuit board needs 12vdc to operate.

With it "on"' the battery gets power from the TV while you are traveling as well. The resistance of the battery also smooths out the 12volts coming out of your converter when you are plugged into shore power.

Also nice to be able to run the water pump during those "rest" stops.

Mike

[nm1oqrz]

Hello All. If you have an older trailer like I have (1988 Excella) and still have the original univolt converter installed you must leave the Master Switch in the ON position while the trailer is connected to shore power (plugged in). The univolt utilizes the battery to help limit the output voltage so it can't harm the 12 volt accessories. If the master switch is in the OFF position and the trailer is pluged in, the univolt doesn't have the battery to limit the voltage and the univolt output voltage could rise up to a level that could damage the 12v accessories.
On newer trailers with a modern converter this is not an issue.
The master switch is really just to be used when you store the trailer.
Happy camping nm1oqrz

[Tartimisi]

Thanks for the info guys. Asking questions is the only way I'll ever learn. AND BOY DO I HAVE A LOT TO LEARN, Thanks again

[ROBERT CROSS]

If I was in your position, 1984 Airstream with the original Univolt Converter.

I would up-grade to a modern 3 stage converter with float charge. It won't overcharge the batteries when plugged in to shore power for extended periods.

Randy at Best Converter will give you the latest/best options.

I used the IOTA DLS 55a IQ4 with great results, a nice feature...it can be used with the batteries out and cables isolated, on shore power without damaging the converter or blowing fuses/breakers.

Good Luck

Bob

[Joe Palmieri]

Hi all, We have a new 20' Flying Cloud with a use/store switch by the door. The switch activates an electric solenoid that disconnects the batteries from the system. The solenoid doesn't draw any juice from the batteries when it is in the (store) position but according to one of the tec's at my dealership it draws almost a full amp the whole time that it is in the (use) position. If you add that to the draw from the radio memory and the propane alarm he said that it draws almost an amp and a half total. We do a considerable amount of dry camping and this doesn't seem like a good idea to have that much drawing on my battery unnecessarily while we are off sightseeing for a day. I plan to remove the solenoid and install a manual marine grade disconnect switch in it's place. I store the AS inside with the battery switch in the (store) position and a small external 1.5 amp regulated maintenance charger hooked to the batteries. When I want to go in the trailer I plug the main power cord into the wall outlet in the garage and the converter supplies the power for lights etc. I have not experienced any blown fuses or any other problems. I do not charge the batteries with the converter while in storage because the charge is unregulated and can cook the batteries if left for too long. I have used this procedure with several trailers with no problems so far.

[Tartimisi]

Originally Posted by ROBERT CROSS

If I was in your position, 1984 Airstream with the original Univolt Converter.

I would up-grade to a modern 3 stage converter with float charge. It won't overcharge the batteries when plugged in to shore power for extended periods.

Randy at Best Converter will give you the latest/best options.

I used the IOTA DLS 55a IQ4 with great results, a nice feature...it can be used with the batteries out and cables isolated, on shore power without damaging the converter or blowing fuses/breakers.

Good Luck

Bob

That is the converter that we bought. In the process of installing it. My husband is having troubles because the wiring that is on the panel does not match the owners Manuel. He's working on that today if you have any advice.

Thanks again

[ROBERT CROSS]

Originally Posted by Tartimisi

That is the converter that we bought. In the process of installing it. My husband is having troubles because the wiring that is on the panel does not match the owners Manuel. He's working on that today if you have any advice.

Thanks again

Can't give any specific advice on your particular install. It may not be as straightforward as ours, plus you never know what mod's the PO may have made.

Good choice on the IOTA, should work great for you.
Did you get it from Best?, Randy may be able to help with the install.

Good Luck!!

[Tartimisi]

Originally Posted by ROBERT CROSS

Can't give any specific advice on your particular install. It may not be as straightforward as ours, plus you never know what mod's the PO may have made.

Good choice on the IOTA, should work great for you.
Did you get it from Best?, Randy may be able to help with the install.

Good Luck!!

Yes. That is who he bought it from. He has a email into randy that will probably confuse the poor guy!

[ROBERT CROSS]

Originally Posted by Tartimisi

Yes. That is who he bought it from. He has a email into randy that will probably confuse the poor guy!

Randy or the DH?

Don't fret, confusion can be good...it tends to solidify memory once the job is finished, he'll remember exactly how it's done and gain valuable knowledge about your new Airstream.

Bob

[KJRitchie]

On the 25fb models with battey disconnect switch by the back door where is the solonoid located? Is it in the converter box under the front bed? I took that box and only saw a ton of cables entering the Parallax enclosure.

BTW, I've just received the Progressive Dynamic swap kit from Bestconverter for the Parallax 7355 and I'll be installing it by this weekend.

Kelvin

[Tartimisi]

Originally Posted by KJRitchie

On the 25fb models with battey disconnect switch by the back door where is the solonoid located? Is it in the converter box under the front bed? I took that box and only saw a ton of cables entering the Parallax enclosure.

BTW, I've just received the Progressive Dynamic swap kit from Bestconverter for the Parallax 7355 and I'll be installing it by this weekend.

Kelvin

Good luck kelvin. My husband is still "studying" the cables and wires. I told him just to jump in and do something. The worst thing that can happen is that he blows a fuse. Right?

[rgwatkin]

I am looking for enlightenment out there? I have a intermittent problem where when I connect to either shore power or generator my batteries are not being charged. I have checked the output of the converter and it is fine running at ~13.3v but intermittently the charge is not getting to the batteries, ie reading on the battery bank of <12.5v. I can toggle the master power switch back and forth and finally get the solenoid to latch properly. I called AS this morning and they said the problem was with solenoid. So...I changed out the solenoid and it does the same thing. So..called the same guy back at AS and told him that I had put a new solenoid in and it did the same thing. He then said "maybe" it is the switch. The switch is an Itell..something and seems to operate as a solid state switch. When not hooked up to shore/generator the switch seems to operate properly ie, turns everything off and turns everything on without any issues. Has anyone out there seen a bad master battery switch on an AS?