2015 24.1 - Chassis Battery cutoff

[RodIndy]

I have a 2015 24.1 with the difficult to access engine battery. Has anyone installed a battery cutoff switch on this battery? Can you share?

[Beau388]

Originally Posted by RodIndy

I have a 2015 24.1 with the difficult to access engine battery. Has anyone installed a battery cutoff switch on this battery? Can you share?

Both Summit Racing and Jeg's sell remote battery cutoff switches. These are active relays. Best to use a latching relay like <https://integrityrvparts.com/products/newmar-rv-133220-battery-disconnect-relay>


I don't know about your coach but my Hurricane has a readily available 100 amp circuit breaker just behind the chassis battery. Tripping it removes all power from the front cap, but the Ford stuff remains powered (starter, engine and transmission computer, etc). With it tripped, the coach's charger will not charge the chassis battery.

[DavidEM]

The new Axis (2021) is wired with a positive on/off switch (not solenoid driven) near the entry step battery box. You could easily install one on yours. Perko and Blue Seas make them.

David

[16ACE27]

Originally Posted by DavidEM

The new Axis (2021) is wired with a positive on/off switch (not solenoid driven) near the entry step battery box. You could easily install one on yours. Perko and Blue Seas make them.

David

CHASSIS battery cut-off.

This is the latching solenoid remote battery cut-off I put in my Wife's Colorado for flat towing. Should work great in an Axis/Vegas 24.1.

EDIT: Forgot the lonk:

https://www.amazon.com/gp/product/B000N8IR5E/

[RodIndy]

Originally Posted by DavidEM

The new Axis (2021) is wired with a positive on/off switch (not solenoid driven) near the entry step battery box. You could easily install one on yours. Perko and Blue Seas make them.

David

You’re saying there is a CHASSIS battery (not house) cutoff switch near the entry step? Picture?

[RodIndy]

Originally Posted by Beau388

Both Summit Racing and Jeg's sell remote battery cutoff switches. These are active relays. Best to use a latching relay like <https://integrityrvparts.com/products/newmar-rv-133220-battery-disconnect-relay>


I don't know about your coach but my Hurricane has a readily available 100 amp circuit breaker just behind the chassis battery. Tripping it removes all power from the front cap, but the Ford stuff remains powered (starter, engine and transmission computer, etc). With it tripped, the coach's charger will not charge the chassis battery.

Yeah, I’ve got the breaker but it doesn’t seem to serve as a complete cutoff solution. What do you mean “front cap”?

[DavidEM]

I missed the "chassis" in the title of this thread and incorrectly answered re the coach battery.

AFAIK, there are no chassis battery cutoff switches on any coach. You don't really want one in the heavy current starting circuit which can hit 500A for a big engine.

Why do you want to cut off the chassis battery, for storage? With an AGM chassis battery in my new Axis it will discharge very little, maybe 2% per month during the winter storage period. If it does discharge more the coach batteries which are being kept up by a 100 watt panel will also keep the chassis batteries charged.

But I don't absolutely trust the low discharge rate and the BIM connection and will start my chassis engine a couple of times each winter and drive it for thirty minutes to charge it up, flush through oxidized ethanol fuel, circulate lube oil, etc.

If you really want to disconnect the chassis batteries, it can be accessed by cutting through the slots in a plywood panel below the passenger flip out table. Search Axis chassis battery on this forum and you will find threads and pics of this operation. Once you can reach the battery, just disconnect the negative terminal.

David

[RodIndy]

I’m “considering “ a chassis battery cutoff switch to circumvent an ongoing problem with my <1 yr old chassis battery going dead every couple weeks. Just noodling.
My MH uses a BIRD and Trombetta isolation solenoid to manage house and chassis batteries. Even if I have a unknown drain on the chassis battery, I’m always plugged into shore power with the use/store switch ON. This should keep the chassis battery charged regardless. Trombetta solenoid was replaced for this problem several weeks ago. Problem persists.

[16ACE27]

Originally Posted by RodIndy

I’m “considering “ a chassis battery cutoff switch to circumvent an ongoing problem with my <1 yr old chassis battery going dead every couple weeks. Just noodling.
My MH uses a BIRD and Trombetta isolation solenoid to manage house and chassis batteries. Even if I have a unknown drain on the chassis battery, I’m always plugged into shore power with the use/store switch ON. This should keep the chassis battery charged regardless. Trombetta solenoid was replaced for this problem several weeks ago. Problem persists.

If the MH is always plugged in and the:
Converter
Bird
Trombetta

all work then the chassis battery should not be discharging if the USE/STORE switch is in USE.

If it is, then a piece of the puzzle is missing. Have you verified that charging voltage is applied to the chassis battery (> 13 VDC) with a voltmeter?

[RodIndy]

A couple more data points on the issue..
When the failure occurs, meaning, I enter the MH and turn the key and nothing happens;
1) there is always 13.56 vdc on the house side of the Trombetta (now new)
2) little to no voltage on the chassis side of the Trombetta
3) the Trombetta is not picked or engaged.. I can jump the 12v feed from the small ring terminal on the trombetta to ground and make the trombetta pick, which is how I start the MH when the failure occurs.
4) the emergency start switch on the dash does not work even though I have fully charged house batteries.

[DavidEM]

Originally Posted by RodIndy

I’m “considering “ a chassis battery cutoff switch to circumvent an ongoing problem with my <1 yr old chassis battery going dead every couple weeks. Just noodling.
My MH uses a BIRD and Trombetta isolation solenoid to manage house and chassis batteries. Even if I have a unknown drain on the chassis battery, I’m always plugged into shore power with the use/store switch ON. This should keep the chassis battery charged regardless. Trombetta solenoid was replaced for this problem several weeks ago. Problem persists.

So with the converter supplying power to the coach batteries with the use/store switch on, then the BIRD should connect the coach batteries to the chassis batteries and keep it charged.

You replaced the Trombetta solenoid. But maybe the BIRD (the system that triggers the solenoid) isn't working. Either replace the Intellitec BIRD or better still replace the whole thing with a Precision Circuits BIM 160.

David

[Beau388]

Originally Posted by RodIndy

Yeah, I’ve got the breaker but it doesn’t seem to serve as a complete cutoff solution. What do you mean “front cap”?

Most class A coaches have a house or body and front and rear fiberglass caps or ends. All of the Thor MC installed items attached to the front fiberglass or front cap are powered by the chassis battery. The radio and power ports are the exceptions.

[taylorbob1]

Originally Posted by 16ACE27

CHASSIS battery cut-off.

This is the latching solenoid remote battery cut-off I put in my Wife's Colorado for flat towing. Should work great in an Axis/Vegas 24.1.
EDIT: Forgot the lonk:
https://www.amazon.com/gp/product/B000N8IR5E/

Yes,
I’ve seen this item mentioned in other threads.
And I remember a Forum member describing an install of this switch on their coach to disconnect “Chassis” battery.

So for Vegas/Axis, if you desire a chassis battery cut-off, then this is the suggested route to follow.

[RodIndy]

Originally Posted by DavidEM

So with the converter supplying power to the coach batteries with the use/store switch on, then the BIRD should connect the coach batteries to the chassis batteries and keep it charged.

You replaced the Trombetta solenoid. But maybe the BIRD (the system that triggers the solenoid) isn't working. Either replace the Intellitec BIRD or better still replace the whole thing with a Precision Circuits BIM 160.

David

Are you saying the BIM replaces both my BIRD and Trombetta solenoid? Looks to me the BIM is a replacement for the solenoid only.
I have 4 wires going into my BIRD..control, ignition, house, ground..

[DavidEM]

Originally Posted by RodIndy

Are you saying the BIM replaces both my BIRD and Trombetta solenoid? Looks to me the BIM is a replacement for the solenoid only.
I have 4 wires going into my BIRD..control, ignition, house, ground..

Yes, the Intellitec BIRD consists of a logic module that senses battery voltage and control signal inputs and then triggers the external Trombetta solenoid. I think that the BIRD also has a chassis input, but maybe that is only to the Trombetta solenoid.

The Precision Circuits BIM has all five inputs including the chassis input as well as the solenoid is integrated into one module. See the attachment for PC's description and wiring diagram. Also look at the MS Word attachment that was written by Thorforum member Judge which describes how Thor wired it incorrectly. I recently changed the wiring as Judge recommends and it works great now.

David

[16ACE27]

Originally Posted by RodIndy

A couple more data points on the issue..
When the failure occurs, meaning, I enter the MH and turn the key and nothing happens;
1) there is always 13.56 vdc on the house side of the Trombetta (now new)
2) little to no voltage on the chassis side of the Trombetta
3) the Trombetta is not picked or engaged.. I can jump the 12v feed from the small ring terminal on the trombetta to ground and make the trombetta pick, which is how I start the MH when the failure occurs.
4) the emergency start switch on the dash does not work even though I have fully charged house batteries.

Sounds like a BIRD failure.

The BIM replace both the BIRD and Trombetta solenoid.

[RodIndy]

Originally Posted by DavidEM

Yes, the Intellitec BIRD consists of a logic module that senses battery voltage and control signal inputs and then triggers the external Trombetta solenoid. I think that the BIRD also has a chassis input, but maybe that is only to the Trombetta solenoid.

The Precision Circuits BIM has all five inputs including the chassis input as well as the solenoid is integrated into one module. See the attachment for PC's description and wiring diagram. Also look at the MS Word attachment that was written by Thorforum member Judge which describes how Thor wired it incorrectly. I recently changed the wiring as Judge recommends and it works great now.

David

Seems like the difference between the BIM and the BIRD is the integration of the logic and solenoid, plus a little more logic that senses a continuous charge and will isolate the batteries until one or the other reaches 80%.
But I still can’t figure out what to do with the existing wires going to my bird..

[ducksface]

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I bought this for the rv but the gator needed it NOW instead of later.
I'll buy another for the RV.
Wiring instructions had some redundancy in them, I think I simplified it all down to three wires.

[RodIndy]

Originally Posted by ducksface

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I bought this for the rv but the gator needed it NOW instead of later.
I'll buy another for the RV.
Wiring instructions had some redundancy in them, I think I simplified it all down to three wires.

Looks great.. Looks like I need to buy some battery cable, right?

[TerryJames]

My plan for the Axis 25.2 Chassis cut off is …
Duralast DL20387 Battery Disconnect Switch
https://www.autozone.com/ignition/ki...tch/422687_0_0

AutoZone switch and a little extra negative cable with mounting low on the left side of the Chassis battery.
Can reach with the hood opened.
Have seen this done on the forum.
(Already put a simple knife switch on the House batteries)