Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Monaco Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 08-02-2014, 09:13 AM   #1
Senior Member
vettehead's Avatar
Monaco Owners Club
Join Date: Feb 2012
Location: Mississsippi
Posts: 184
Big Boy is not charging Chassis Batteries

I had trouble some time ago with the Big Boy relay not doing it's job, so after some research, I removed an cleaned the contacts of the big relay. Problem solved for almost a year.
Now I notice the chassis batteries are not receiving a charge hooked to shore power, 11.9 volts. Good charging rate with the engine running, 14.2vdc. House batteries are staying around 13.8 vdc while hooked to SP. Have load tested all batteries, good.
Thru research here I understand the ISO Green LED light in the Rear Run box should be lit, and a "hum" from the BB and it should be warm. Mine is not.
The question I have is what controls this part? Is there something that turns it off?
Phil & Carolyn (Retired)
2006 Monaco Executive
ISX Cummins 525 hp
vettehead is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-02-2014, 09:30 AM   #2
Senior Member
Skip426's Avatar

Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 28,835
I'm not sure if Monaco, uses a BIRD system ( Bi-directional Relay control module ) the 4"x4"x1" module should be clearly marked and close to the big relay, attached by a small gauge wire to the small posts on the big relay. Can you see anything with those markings?
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 08-02-2014, 10:12 AM   #3
Senior Member
Gorlininc's Avatar
Monaco Owners Club
Join Date: Jun 2012
Location: Merritt Island, FL
Posts: 1,742
Yes. The ISO green light should be on.
You say you are getting a huum from the bigBoy?
Is there 12 V on the BB coil? If the BB is getting power then the BB is probably bad.
If the BB is not getting power to the coil then your BIRD is not operating.

are there any heavy drains on your 12v system? The job of the BIRD isolator when on shore power is to protect your house batteries from being drained down by your chassis batteries and visa versa. Your chassis batteries at 11.9 v tells me something is draining them down. I don't know how long they have been sitting. Why are the chassis batteries so low?
Gorlininc is offline   Reply With Quote
Old 08-02-2014, 02:16 PM   #4
Senior Member
Skip426's Avatar

Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 28,835
The system also works in reverse, to stop high loads in the coach from running down the chassis batteries.

Operational info in this file , pages 13 & 14.
Attached Files
File Type: pdf Bird system info.pdf (1.54 MB, 66 views)
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote

batteries, charging, chassis

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Coach batteries not charging Lance7 Fleetwood Owner's Forum 15 06-26-2014 12:45 AM
Charging rates in AGM batteries MN_Traveler Class A Motorhome Discussions 11 04-09-2014 07:09 PM
Batteries not charging and keep tripping the charger illusionist RV Systems & Appliances 5 02-18-2014 05:38 PM
Charging house batteries manitou Newmar Owner's Forum 5 12-13-2013 10:41 PM
Big Boy and BIRD - Learned Something Not in the Documents distaff Monaco Owner's Forum 4 10-27-2013 09:46 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 07:30 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.