What Charges the House & Chassis Batteries When

[Oneilkeys]

Originally Posted by petefoss

So my chassis battery went dead. I'm plugged into shore power and my house batteries are now at 13.5 while on shore power. But the chassis battery is not charging. Sounds like a BIRD issue?

So best way to charge chassis battery for now is to get off shore power and put an external charger on the chassis battery? I don't want the BIRD to start supplying DC at some point to the chassis battery while the other charger is connected?

Pete

You don’t have to worry about that. People run their generator and their engine at the same time and the Trombetta will be open.

[petefoss]

I tried my external charger but the battery keeps faulting the charger. I assume due to the fact it was at zero. Resting it's less than 4V so toast. I may try the engine to see if the alternator can do anything.

[Oneilkeys]

Originally Posted by petefoss

I tried my external charger but the battery keeps faulting the charger. I assume due to the fact it was at zero. Resting it's less than 4V so toast. I may try the engine to see if the alternator can do anything.

Careful about starting the engine with 4V. I started a car with a very low chassis battery and it destroyed the engine computer. Cost me several hundred dollars.

[dogday51]

Does the generator need to be running in order to use the emergency start switch to start the engine? I installed and plugged in the MH to a dedicated 30 amp circuit from the house last week. The coach battery has a full charge but the chassis battery has no charge. Lights on the outside of the MH do not come on when you open the door so they are apparently connected to the chassis battery. I hear a rapid clicking underneath the dash near the emergency start switch when plugged in to shore power. Anyone have an idea what that may be related to?

[Oneilkeys]

Originally Posted by dogday51

Does the generator need to be running in order to use the emergency start switch to start the engine? I installed and plugged in the MH to a dedicated 30 amp circuit from the house last week. The coach battery has a full charge but the chassis battery has no charge. Lights on the outside of the MH do not come on when you open the door so they are apparently connected to the chassis battery. I hear a rapid clicking underneath the dash near the emergency start switch when plugged in to shore power. Anyone have an idea what that may be related to?

If the chassis battery is really dead, you need to put some charge on the chassis battery before you try to start start the RV with the emergency start switch. You can do that (if everything is working correctly) by either plugging into shore power or running the generator. That will open the Trombetta (or BCC or BIM) and charge the chassis battery. If you wait long enough, you will charge the chassis battery enough to start the RV by itself. Have you checked the 100 amp breaker in the engine compartment? If it is tripped, you will get no voltage from the chassis battery to the coach, nor will you charge the chassis battery. You need a volt meter to check and see if your charging system is working correctly. Make sure your use/store is in the Use position.

[Oneilkeys]

If the chassis battery is just down a little, but enough that it will not start the RV, the emergency switch should provide enough juice to the chassis battery from the coach batteries to start the RV without running the generator. However, it sounds like either your chassis battery is too discharged to start the RV even with a boost from the coach batteries thru the emergency start switch, or your Trombetta is not opening or your 100 amp engine breaker is tripped.

[dogday51]

Plugged in MH last night to dedicated 30 amp circuit from home. Still no power to start engine or recharge chassis battery. Where exactly is the 100 amp breaker and is it simply just flipping a switch to reset.

[Oneilkeys]

Did you have the use/store switch in use? The batteries will not charge if the use/store is in the store mode. There are two 50 or 100 amp breakers. One is located in the back left corner of the coach battery box under the stairs. The second is located on the left side of the engine compartment (when looking at it from the front grill). They have a button and a red or yellow flag or piece of plastic that sticks out from the breaker when it is tripped. Pushing the button deploys the flag so that you can see it. Physically pushing the flag back in closes the breaker so that current can flow from the batteries to the coach.

[Oneilkeys]

There are lots of different kinds of 50/100 amp breakers but this is what they look like. Yours may be a different size and/or shape but they all have the button and “flag”. Do u have a volt meter? You really need one to diagnose your problem if the breaker does not solve the issue.

[Jeff H]

I'm new to RV'ing, We just purchased this RV last Sept. used. On our first trip from Florida to Texas, I noticed with key in ignition and RV engine running, I couldn't switch to "Use", assumed that was normal. But I remember first getting it and I could switch it from store to use and I had power from house batts. I noticed by the end of our trip recently, that I can only get house power with Generator or Shore power. I took it back to the dealership I got it from, they state the problem is the "The Battery Cutoff switch is no good." where is that Battery Cutoff switch on the 2017 Thor Vegas 25.3 located? Anyone got pictures of it? I'm assuming it's mounted near the relay panel, or behind it. Because I can't find it yet near the chassis battery, or near the house batts. Can you experts lend a hand to an ex AF avionics electronics guy? I can fix B1 auto pilot systems, but can't find a simple component on an RV!

Originally Posted by Oneilkeys

From Ed's first post in this thread.
When the BIRD senses 13.1 volts for 2.5 minutes on the chassis battery the relay isolator will close sending charging current to the house batteries (alternator providing charge to house batteries. Going the other way when on shore power or running the generator when the BIRD senses 13.1 volts for 2.5 minutes on the house batteries the relay isolator will close sending charging current to the chassis battery (generator or shore power charging the chassis battery).

It is easy to check if the system is working. If the charging system is working correctly, after About 2.5 minutes the Trombetta will open connecting both battery banks for charging. If that happens, the voltage at both posts of the Trombetta will read the same on a volt meter. If they do not, the Trombetta is closed. After the charging system is shut off, the voltage in the batteries has to drop to 13.8 v (I believe) and the Trombetta automatically opens. If you have a load on the coach batteries The voltage readings from the two large a Trombetta posts will quickly read differently.
I could be wrong, but i think that the way Thor has this wired, the emergency start switch plays no part in the BIRD/Trombetta operation. I think it is wired completely separately and physically connects the two battery banks with a wire running for one bank to the other thru the emergency start switch. When the switch is pushed, it physically connects the two banks and when the switch it let off, it separates them. The five wire BIRD has a wire that acts as that switch and closes the Trombetta, but in the Axis, I'm not sure the emergency start switch closes the Trombetta. I think it works separately from the Trombetta to connect the two battery banks. I am not sure of that, but from fooling around with the system, I think that is the way it works.

[16ACE27]

The battery cutoff switch is the USE/STORE switch by the entryway. Isn't this "no good" switch covered by warranty?

[Oneilkeys]

It could also be the 50 or 100 amp breaker located in the back left corner of the battery box (at least in my 2014 Vegas and 2016 Axis). In my 2014 Vegas I popped that breaker and only had 12v power to the coach when on shore power or generator and the batteries wouldn’t charge. The breaker has a button which deploys a red or yellow “flag” indicating the breaker is open. Push the “flag” back in and the breaker is closed. It could be either this is tripped or not functioning or the store/use switch is bad.

This is a picture of a typical breaker. Yours could be a different size or shape but all have the button and flag.

[Oneilkeys]

This is from a different thread today from Ed Felker on the location; if the solenoid hooked to the Use/Store switch and its location in his Vegas 24.1.

[Oneilkeys]

It is most probably one of these two devices. If you have someone cycle the Use/Store From use to store and back you should hear the loud click of the solenoid as it opens and closes - if is working correctly. If you have a volt meter you can check the voltage on both sides of the 50/100 amp breaker to see if that is working.

[Jeff H]

Not under warranty, due to being second owners, and a dealership claiming we would be covered buying an expensive extended warranty. But the reason I couldn't understand the Use/Store switch is because the RV Service tech wrote the Battery Cut off switch is bad. But I hear the correct noise coming from the Breaker/Relay assy. So It's obviously another component that is truly the culprit. I believe it's a solenoid near the Breaker/Relay center.

[Jeff H]

Originally Posted by Tfryman

The battery cutoff switch is the USE/STORE switch by the entryway. Isn't this "no good" switch covered by warranty?

So, I read so much about this, I'm stuck in the forest and can't see the trees.

I think with some of these posts, I'm leaning in the right direction with the few posts given.

I just need to find the solenoid.

[Jeff H]

Originally Posted by Oneilkeys

This is from a different thread today from Ed Felker on the location; if the solenoid hooked to the Use/Store switch and its location in his Vegas 24.1.

This is what I think is my issue. If I can find this solenoid component and test it, I think it's the problem part. Any suggestions on trouble shooting it?

The dealership was misleading me, they also wanted to replace my entire windshield wiper assembly for $780 for parts alone, as the driver side actuator arm broke behind the front grill and we had no dr. side wiper for the last 500 miles of our drive home. I ordered just the part I needed online for $25.90. FL OutDoor is not my best deal I ever made, that's for sure.

I'm wondering if I got a huge lemon?

[lazinskm]

Thanks oneikeys for the Picture. I am the one that started the other thread. I still cannot find this breaker in my Thor class c 28z. My batteries are under the step on a metal tray I would not call it a box. If anybody has an idea where this breaker would be please let me know

[Oneilkeys]

Originally Posted by Jeff H

This is what I think is my issue. If I can find this solenoid component and test it, I think it's the problem part. Any suggestions on trouble shooting it?

The dealership was misleading me, they also wanted to replace my entire windshield wiper assembly for $780 for parts alone, as the driver side actuator arm broke behind the front grill and we had no dr. side wiper for the last 500 miles of our drive home. I ordered just the part I needed online for $25.90. FL OutDoor is not my best deal I ever made, that's for sure.

I'm wondering if I got a huge lemon?

If you stand inside your coach and have someone turn the use/store on and off you should be able to hear the solenoid “thunk” and find it. If you do not hear it, it probably is the problem. When you find it, one of poles with the large wire attached goes to the batteries and the other to the coach. If it in the store position, one of those poles should have approx the same voltage as the batteries and one should show no volts with a volt meter. Carefully, both poles are positive and when the use store is in use, a lot of amps flow thru there. Positive wire to one pole and negative wire to ground from the volt meter. If you’ve never done it, have someone show you the first time. When the use/store is in use, both poles should show the same voltage - if the solenoid is working. If you get no voltage on either pole, the 50 Amp breaker is probably the culprit.

[lazinskm]

Thanks for this info, and the warning!!! I assume that if I disconnect the batteries and are unplugged I should be fine in replacing it (after I find it). I am pretty sure this is the part...


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