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MG1 · 07-15-2021, 06:54 PM

Greetings,

Question from a Newbie. I have a 2021 Canyon Star Front Engine Diesel 3927. When boondocking and running the generator my chassis batteries rapidly discharge. If the engine is running both banks of batteries charge appropriately. Also, the battery boost does not seem to be working unless I am supposed to hold it for an extended period of time (longer than 20 mintues). I jump started the coach yesterday evening and let the batteries charge. Went out this morning and started the generator and turned on an AC. Returned at lunch time and the chassis batteries were down to 7.8v. Coach batteries fully charged. I went out this evening and tried to start it using the battery boost with no luck. Held it down for 20 minutes. Going to have to jump it again. Please help

MrMark52 · 07-15-2021, 07:22 PM

Does your coach have a transfer switch or is there a receptacle to plug the shore power tether into when using the generator?

MG1 · 07-15-2021, 07:38 PM

Quote:

Originally Posted by MrMark52

Does your coach have a transfer switch or is there a receptacle to plug the shore power tether into when using the generator?

It has an automatic transfer switch.

D20 · 07-15-2021, 07:54 PM

Sounds like something is not working with the BIRD and or Isolator Relay. I don’t know which model BIRD you have, but if it is an Intellitec, then check here for model you have and check the documentation. They do have a troubleshooting recommendation for when the chassis battery drains in the documents.

https://intellitec.com/products/#battery-disconnects

MrMark52 · 07-15-2021, 07:56 PM

Am assuming since the coach is a 2021 that the batteries are hopefully still good.

I’m kind of suspect of the transfer switch unless you also have an inverter and your running your AC unit(s). In which case, how many coach batteries do you have and what voltage/amp hour rating.

MG1 · 07-16-2021, 10:31 AM

Quote:

Originally Posted by MrMark52

Am assuming since the coach is a 2021 that the batteries are hopefully still good.

I’m kind of suspect of the transfer switch unless you also have an inverter and your running your AC unit(s). In which case, how many coach batteries do you have and what voltage/amp hour rating.

We do have an inverter and are running the AC. The coach batteries read fully charged at around 13.5 v or so. I suspect it is either the module for the B.I.R.D or the isolator relay. I’m more suspicious of the relay given the fact that the battery boost is not working. Now where the question is where are these components ? Thanks for the input so far.

MrMark52 · 07-16-2021, 03:28 PM

Quote:

Originally Posted by MG1

We do have an inverter and are running the AC. The coach batteries read fully charged at around 13.5 v or so. I suspect it is either the module for the B.I.R.D or the isolator relay. I’m more suspicious of the relay given the fact that the battery boost is not working. Now where the question is where are these components ? Thanks for the input so far.

So I am thinking you are running the AC units from shore power, correct?

When you’ve measured battery voltage, is that with a separate voltmeter or something installed on the coach?

Was battery voltage measured with shore power connected? Or with genset running? Or with the engine running?

What battery voltage to do measure without any external power sources, including the genset and engine alternator?

Have you isolated the batteries in and made a voltage measurement directly on the battery terminals?

Your converter (120VAC to 12VDC) is normally found in the electrical bay near the breaker panel. It may have circuit breakers or fuses or both. Check them.

Assuming you have an inverter (12VDC to 120VAC) it is normally found in the same bay, but not always.
Your inverter looks for 120 VAC on the incoming shore power line. If it doesn’t see it, it switches its own internal transfer switch and pumps 120VAC into the coach using the 12VDC from the batteries.

hohenwald48 · 07-19-2021, 12:00 PM

I have a 2019 gas CS so probably not relevant but my "BIRD" relay is located on the front of the firewall up high above the engine. A real pain to get to and I did have to change it after about a year.

MG1 · 07-21-2021, 06:06 AM

Thanks for all the input. I actually stumbled onto the culprit and it turned out to be an easy fix. The fuse for the battery boost/courtesy lights was blown. If you remember, part of the initial issue was that the battery boost was not working. We had a short in the passenger seat a couple months ago that blew the automatic resetting breaker. The dealer fixed the short and the breaker. I suspect they caused the fuse to blow (who knows but they were messing around right by the relay). Hopefully it doesn’t continue to blow. Any way, the system is working properly now. I am very surprised that the fuse for the battery boost caused the entire system to drain the chassis batteries but I’ve tested it for a few hours a couple times now and no issues.

Also, the B.I.R.D components are in the fuse box up above the radiator. Sounds like the same location as on the aforementioned 2019.

The thing that clued me in to this fuse was the lack of an audible click when I push the battery boost button.

Thanks again. Hopefully this helps someone at some point in the future.

MrMark52 · 07-21-2021, 07:39 AM

Thanks for updating and that you found the problem!

"007" · 07-21-2021, 06:51 PM

Welcome to the forum, MGI
This sticky link will give you many answers for items in your coach and the battery charging systems which with new coach should be a b.i.m.
That 5 amp fuse for boost is hard to see and many miss finding it.
If the chassis battery didn't charge would most likely been a problem with the solenoid of that charging system.
Good find, enjoy the coach and safe travels.

LoPro · 05-29-2023, 12:03 PM

[QUOTE=MG1;5840230]Thanks for all the input. I actually stumbled onto the culprit and it turned out to be an easy fix. The fuse for the battery boost/courtesy lights was blown.”

I have this exact problem on my CS3927 FED - where is the fuse you replaced? Did it continue to blow?
Thanks!!

Never mind - found and replaced the fuse but the battery booster is still not working and the batteries are dead.