No 12v power on the house side

BobnDonna · 06-26-2023, 09:03 PM

I have a 2003 Itasca Horizon 36LD that I’ve just owned for a couple of weeks. There is no 12v power on the house side. The batteries are fully charged. I got in it today and tried to start the generator and everything was completely dead. No 12v at all. I flipped the auxiliary power switch and everything was back to normal. I checked all the breakers and nothing was tripped. When I turn the auxiliary power switch off the generator dies and everything goes black. It’s the same whether I’m plugged into shore power or not.
Any suggestions?

**creativepart** · 06-26-2023, 09:32 PM

The poorly named “Auxiliary Battery” switch is your 12v disconnect on the RV.

So, yeah, you’re turning off the 12v connection to the house batteries. Hence, losing 12v power.

The A/C cuts off because the thermostat runs on 12v and will shut down without it.

Your Operator’s Manual details this in section 2-11. Here’s a screenshot of that info:

BobnDonna · 06-26-2023, 09:55 PM

Quote:

Originally Posted by creativepart

The poorly named “Auxiliary Battery” switch is your 12v disconnect on the RV.

So, yeah, you’re turning off the 12v connection to the house batteries. Hence, losing 12v power.

The A/C cuts off because the thermostat runs on 12v and will shut down without it.

Your Operator’s Manual details this in section 2-11. Here’s a screenshot of that info:

OK, so I'm a moron. It was dark when I got in the camper and I must have hit the auxiliary battery switch instead of the generator switch. Then of course after that nothing would work. I thought the auxiliary battery switch was a switch that allowed you to use the chassis battery for the house side if the house batteries were running low on juice. So when I flipped it, thinking I was using the chassis batteries to start the generator instead of the house battery, that train of thought sent me down a rabbit hole.

Thank you for your help!

**creativepart** · 06-26-2023, 10:06 PM

Quote:

Originally Posted by BobnDonna

I thought the auxiliary battery switch was a switch that allowed you to use the chassis battery for the house side if the house batteries were running low on juice.

That would be the appropriately named “Auxiliary Start” switch. And, it is for combining your house and chassis batteries. Using it can help two different ways. One like you said, help add power from the chassis battery to augment weak house batteries but more importantly to use the house batteries to help start the motor when the chassis battery is low.

All of this is in your Operator’s Manual. Do you have one? It’s very complete and worth reading multiple times. Honest.

If you don’t have one I can post a link to an online version, if you’d like.

Wait I have a link handy. Her it is:
https://www.winnebago.com/Files/File.../03Horizon.pdf

**creativepart** · 06-26-2023, 10:09 PM

They have renamed that switch many times over the years. On my 2017 it’s called the House Battery Disconnect. A much better name than how it’s worded on your RV.

BobnDonna · 06-26-2023, 10:26 PM

Yeah, I don’t think I would have misinterpreted it if it was named House Battery Disconnect. I do have the owner’s manual. Moving from a small travel trailer to a class a is a bit overwhelming. Reading the owners manuals for the house side and the chassis side is kinda like drinking from a fire hydrant. A lot of it gets past me.

Morich · 06-27-2023, 07:21 AM

You are right about the manuals when it is so much new stuff!
But it's one that will help in a lot of ways but also can give us the wrong idea because it may mask some things that will then sneal up on us.

The battery disconnect switch is a big help but may kill us at the same time! It DOESN'T disconnect all the drains on the battery!
Isn't that a whoops when we think we are all in the clear and store the RV?

Yes, it disconnects most of what we think of but it also leaves too much to trust the RV won't be dead after a month or so! Safety items are a big one as propane detectors, CO detectors and the safety stuff that would leave them liable are left on, even when the disconnect is turned off!

For the new user, there should be a big stamp on the back of our hand, saying to watch the batteries or they go dead! Leaving the RV plugged in and the disconnect switch ON will let the converter charge the coach batteries but may also overcharge them, dry them out and kill them! On many RV, it also does nothing to keep the chassis battery charged and things like radio presets, ignition, and any automatic stuff like doors may also run it down!
I'm guessing about 50% of new users lose or damage the first set of batteries and that is a real waste as it can be avoided by careful watching what the voltage on each group is doing and keep it up while stored!

HINT? To give everything the best shot at working right when using high current things like starting the generator or the jacks, one sure way to make sure it all has the optimum battery power to work, is to start the RV engine first. It start much better/quicker than the generator which may take a bit to get fuel pump to the right places and it also automatically connects both the coach and chassis battery to the engine alternator as a way to recharge it all. That combo of all combined gives stuff the best ,really good voltage to avoid them trying to work with possible low voltage. Motors, etc do heat up much more and quicker when working with low voltage so just better to give them the good stuff when we can.

Don't worry about me! I'm just kind of paranoid but like to warn you !
It's a learning curve and takes a few bumps to get started but it's a fun ride once you get going!