Disc Brake Owner Alert

[BryanValRox]

Folks, just wanted to get the word out. Please beware that the current online owners manual doesn’t contain any special instructions regarding disc brake operation.

Specifically, it is imperative to tow your coach with the truck lights on. While this might be obvious to some, there should be some sort of call out in the owners manual regarding the reason why.

We ordered our 2024 310RL with the disc brake option, it appears this option drives the need for a factory installed DC/DC battery charger to be installed as well. I assume this is to keep the battery optimally charged do to the added draw that the brake actuator pump places on the electrical system.

This charger requires a Ignition Switched Based ”Trigger Wire” to turn it on and in turn charge the battery. It appears that the factory is attaching the trigger wire to the light circuit in the 7 pin junction box on the rear of the pin box. So unless the truck lights are on there would be no battery charging to the coach. (other then the standard solar at least in our case)

The trucks charge line connects to the 7 pin box and in turn to the DC/DC charger inlet(+) .

This DC/DC is also an isolator and will not allow any current to pass thru it unless it is activated by the trigger wire.

I see this missing documentation as a big safety miss, as the battery voltage would be depleted with each brake activation and without charger activation there would be no voltage to charge the battery). Voltage could get low enough to prevent proper brake activation.

Just wanted to get the word out to owners and hope that the A-team will update the owners manual with this critical safety information.

Lights on for safety and charging Allies!

 

[Hrkdrivr]

Thanks for the heads up, Bryan! How did you figure this out?

I noticed the DC/DC charger but had no clue what it was for. We have upgraded solar and a generator and the documentation for the whole electrical system is sorely lacking.

We have a 2024 395DS and always drive with the lights on, thankfully.

 

[BryanValRox]

So, I was trying to figure out why the green light would would never come on, on the DC/DC charger with my current truck plugged in(lights were not on, I keep them on the auto setting, and am waiting on a new truck that can tow this coach). So, I started tracing the light Blue wire (in my case)trigger wire and found that it lead to the green terminal inside the 7 pin junction box on the rear of the pin box. A volt meter on either side of the DC/DC confirmed that it was acting as an isolator as well(Renogy Manual calls this out as well). So, I turned the lights to manual on and the DC/DC activated. I can’t say that I agree that this is the best strategy and have relocated my trigger wire to the charge line of the 7 pin. The charge line of the truck is in fact switched(in my case) and effectively works the same way as the factory wired it, without the need for the lights to be on(we all forget from time to time or leave them on auto). Because the charge line is switched, the DC/DC will shut down when the key is off and the isolator feature will prevent any power transferring from the truck to the coach with the key off.

Also, just a heads up Alliance has issued a recall for a wiring change to the breakaway switch for units recently build with disc brakes.

Hope you are enjoying your new coach!

 

[Gord&Cindy]

just out of curiosity what is the charging rate of the DC-DC charger? What make/model do they use?
I was thinking of installing one myself but didn't think the existing charge line would supply enough current.

 

[BryanValRox]

just out of curiosity what is the charging rate of the DC-DC charger? What make/model do they use?
I was thinking of installing one myself but didn't think the existing charge line would supply enough current.

In our case the coach came with a Renogy 20 amp DC/DC And it is factory installed “inline” from the 7 pin to the battery buss. Agree that you need to ensure proper wiring practices are followed if you perform any electrical additions or modifications. Also as I think you are alluding to, the truck charge line ampacity needs reviewed as well.

 

[Gord&Cindy]

Our 295MK didn't have lithium batteries (actually, it didn't have any batteries) so I paid the extra and got one lithium installed before we took delivery. I then disconnected the charge line from the truck so the lithium battery wouldn't draw an excessive amount of current from the truck. I have been looking at installing a DC-DC charger but I was looking at a higher amperage unit from Renogy that would require new wiring from the truck batteries to the charger in the trailer, the wire costs as much if not more than the charger.
I have been trying to determine if the truck's TRM (Trailer Module), the thing that controls the trailer connector lights/brakes/charge, has some sort of current limiting ability but the only thing I see is a 30A fuse.
This looks like a viable option so I may have to investigate it further.
Thank you very much for the information.

Gord

 

[BryanValRox]

Our 295MK didn't have lithium batteries (actually, it didn't have any batteries) so I paid the extra and got one lithium installed before we took delivery. I then disconnected the charge line from the truck so the lithium battery wouldn't draw an excessive amount of current from the truck. I have been looking at installing a DC-DC charger but I was looking at a higher amperage unit from Renogy that would require new wiring from the truck batteries to the charger in the trailer, the wire costs as much if not more than the charger.
I have been trying to determine if the truck's TRM (Trailer Module), the thing that controls the trailer connector lights/brakes/charge, has some sort of current limiting ability but the only thing I see is a 30A fuse.
This looks like a viable option so I may have to investigate it further.
Thank you very much for the information.

Gord

One thing I have learned since embarking on this adventure is that it takes a village to understand all of the nuaunces, of these coaches. I am glad to offer any experiences that I have encountered, but admittedly I have a lot to learn myself on these things. Greatfull that this forum exists to help solve some of the mysteries we all encounter.

Best regards,
Bryan