12v disconnect switch

[TangoMike]

I have a 2003 Winnebago Adventurer 35u F53 chassis.  When I plug the coach into shore power and turn the Aux battery disconnect switch (at the entrance stairwell) to off, this puts the batteries into storage mode and I continue to have power since it is plugged into shore power.  But lately when I have the coach plugged into shore power and turn the 12v switch to off, there is no power to the coach (except of course the engine).  When I turn the 12v switch back to on (still connected to shore power), my electrical panel (powerline EMS status panel) comes on and all of my 110 power is working (microwave, A/C system, etc.).  When I turn the switch off or on, I hear the standard "clunk" sound.  When I turn the 12v switch to off, disconnect the shore power and wait a few minutes before plugging back into shore power, the 110 AC comes on.  Yet when I turn the 12v switch to on then off, the electrical panel (showing that I have 110 power) goes out.  Is it the switch, the ATS (automatic transfer switch) or a bad battery disconnect relay?

 

[TangoMike]

I forgot to mention when the generator is running and I turn the 12v switch to off, the generator shuts down.  The EMS panel had been replaced at one point in the past, long before I bought this coach, probably when it was still under warranty.

 

[TangoMike]

Another thing I discovered - when I hold the 12v switch all the way down, the lights stay on in either 12v or shore power.  When I let go of the switch all power goes off.

 

[SargeW]

I would start checking you house battery bank. Disconnect the negative battery cables and let them sit for about an hour. If they are wet cell batteries with caps, get a hydrometer and check each cell in the back to see if one or more are dead or shorted. If they are sealed you may need to take them somewhere to be load tested.

 

[Gary RV_Wizard]

12v coach power comes from either the house battery (which you control with the disconnect switch) or the converter/charger (which converts shore power 120vac to 12dc). Sounds to me like the converter isn't converting, or at least the converter output isn't getting to the fuse panel.

Many things in the RV won't work without any 12v because the control circuit boards all use 12dc power to operate. Therefore things that nominally work on shore power still do not work unless 12v power is also present.

 

[YLBlues]

If you?re connected to shore power, why do you want to disconnect the 12 V power anyway?  Not being a smart-ass, just wondering what the benefit would be.

 

[TangoMike]

110v shore power charges the batteries but there is no "float" so it can overcharge the batteries.  I learned that last year and had to replace both batteries.  Batteries are new, are fully charged and power the coach when shore power is disconnected.  When I turn the salesman switch to off with the coach is connected to shore power, I get no power at all.  If the generator is running and I turn the salesman switch to off, the generator stops.

 

[TangoMike]

By the way, ALL things work in the coach when the shore power is connected, including all things which are 12v.

 

[Bobtop46]

That is the way it is designed.  Leave the salesman switch alone.  The only time you use it is when you put the RV in storage.

When running the generator and you turn the switch off you disconnect the batteries from the system killing the generator that needs 12v to the control board, because the generator powers the outlet that powers the converter (12v charge the battery) which provides the 12v to the control board.

When plugged into shore power, the shore power, powers the converter that charges the battery, and the rest of the 12v systems in the RV.  everything works.  You can even remove the batteries while on shore power and still have 12v to the RV.

When on shore power if the lights get dim and weak and things start to die that indicates a problem with the converter because it is no longer charging the batteries, and the batteries die.  You can make all this happen by messing with the salesman switch when plugged in.  The batteries don't get charged. 

 

[John From Detroit]

Ok I just typed this next line for another post.. How most RV's are wired

Battery--Fuse or breaker--SWITCH--Rest of rig including generator fuel pump and converter.

now.. the Switch is the battery discounnect switch.. The Generator powers the converter same as shore power (Via a circuit breaker often marked CONV on the breaker panel) and that in turn powers the lights. Fans. Water pump. Furnace. control power for fridge and water heater and Air Conditioners (in some cases) and the Generator fuel pump

You have described one of three or 4 things.

1: Tripped ConV circuit breaker (To fix reset)
2: Blown Reverse Polarity Fuses on the Converter  (usualy 30 amp fuses and usually more than one MUST all be replaced while unplugged Disconnect switch off if they are blown)
3: Blown converter (Replace with a nice Progressive Dynamics.. 9200 or 4600 depending on if the converter is a stand alone or part of the power center)

And in my case #4.. Now My converter has failed several times due to #4

It is a plug in model... That is there is a 15/20 amp outlet next to the converter and the converter has a cord. Just like any appliance only mine has a 20 amp plug that fits nicely in the socket. also comes easily OUT of the socket when I accidently snag the cord  Then it don't work no more. (Till I plug it in).

 

[TangoMike]

I had a bad switch and a blown fuse.  Problem solved.  Thanks to all who replied.