Recent Posts

1

Technical Support / Re: House Batteries Not Charging

« Last post by Scott Shearer on Today at 11:39:27 AM »

Bill,

I would first attempt to find out why the house battery bank is not charging while connected to shore or generator power.

When on shore or generator power, the house battery bank charges independently of the BIRD system (PCB6), drawing power directly from the inverter/charger. In fact, the house batteries will charge regardless of the position of the house battery disconnect switch.

First, verify that your inverter is set to charge mode and the remote panel is displaying a charge voltage. Then, you can follow the charging path by inspecting the large lugs located at the bottom of the rear run box. Charging current from the inverter enters the rear run box at lug #5, passes through the high-amperage circuit breakers, then continues to lug #4, on to the battery side of the house battery disconnect switch, and finally the house battery bank.

There should be charge voltage present at lugs #4 and #5, the high-amperage circuit breakers, the battery side of the house disconnect switch, and of course the batteries.

If there is no power at lug #5, check the output terminal (red cable) on the invertor.

Regarding rear run box PCB6 (BIRD-BCC), pressing the yellow ISO RLY SW on PCB6 will not lock in the Big Boy relay; the function is momentary, like the Boost Switch located on the dashboard. The Big Boy will not lock in until PCB6, pin 2 OR pin 3 on the 8-pin connector, sees 13.3-volts or higher for at least 12-seconds.

-Scott

2

Technical Support / Stuck swivel fittings on air tank

« Last post by Lyle McIntyre on Today at 05:37:50 AM »

I am new to the BAC.  We recently bought our first diesel pusher.  2005 Beaver Monterey.  I have been reading technical support bulletins all winter in preparation of getting the motorhome. I must say, I am very impressed with the support in this community.   

First post. 

I have been chasing air leaks.  Found several on the main tanks which are located on the passenger side storage between the frame rails.  I have read many posts where members routinely curse the swivel push-to-connect fittings.  Clearly with good reason.  There are 5 leaking swivel connections on the two tanks.   They all leak at the swivel.  As luck would have it most of the fittings are located near the top of the tank with minimal clearance to the motorhome floor above.  Some fittings I was able to remove, but others are stuck fast.   The fitting above the 7/8 wrenching surface is larger, so there is limited space to get a wrench on it.   I have pulled as hard as I dare using a 7/8 open end wrench.  I can feel the brass starting to deform.   There is very little room to get ahold of it with anything else.  My typical stuck bolt go-to ideas like breaking out the torch do not seem advisable in such cramped spaces.  I did try some penetrating oil,  but given the amount of sealant on these fittings, I wonder how well it will be able to penetrate. 

I searched the forum as I assume I am not the the only one to face this predicament.   I did not find any articles other stuck-fittings techniques or tools I should try.   Can you point me to posts if they exist or share your advice.  Your wisdom would be very appreciated. 

PS:  I hope to never have to service any of the fittings on the far end of the tanks as they extend into the Hydro-hot bay, overtop of the fresh water tank.  How does one access those fittings should they become a problem? 

   

3

Technical Support / Re: House Batteries Not Charging

« Last post by Frank Bergamo on Today at 01:35:12 AM »

No green light on when plugged in, or on generator power is probably a board failure. No green light on when unplugged or generator not running is normal. Need to determine what is going on with above scenarios. If board is bad, a jumper from chassis bank to house bank positive terminals is a work around until you can get it working properly. Your batteries will not be isolated, but that can be managed accordingly. Hope this helps, good luck. Found this, it might help you,
When connected to shore power or when the generator is running you should have power to the #2 pin on the eight pin connector on the right side of the board. The #1 pin is ground and the #3 pin is powered on when you turn on the Ignition Switch. Pin #4 is from the battery boost circuit, Pin #5 is the Domestic power circuit. Pins #6 & #7 are blank. Pin #8 is a ground circuit.

The six pin connector on the top of the board powers up the relays. The left pin is Pin #1 and is ground, Pin #2 powers up the Big Boy Relay, Pins #3-4-5-6 power up the two Domestic Relays to the right of the Big Boy Relay. When working properly you should measure about + or - 4.6vdc on Pin #1 when the Board is powered up and the Big Boy Relay is working.

If the BB is powered up and running correctly, you should have around 4.5 to 4.8 vdc on pin 1 of the 6 pin connector. You should also have that same voltage on pins 1, 4, 5 & 8 on the 8 pin connector.

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Technical Support / House Batteries Not Charging

« Last post by Bill Heffernan on Today at 01:13:00 AM »

We are out on our first trip of the year and our house batteries are not charging while on shore power nor do they charge while driving. All of the connections are good and clean. The battery disconnect switch is on. I recently cleaned up the Big Bird and noticed that it is not on. Nothing is lit on PCB 6. When I press the ISO RLY SW button, it immediately trips back off. Electrical is not one of my strong suits, this is as far as I'm able to get. Any thoughts/recommendations. As always thanks for the advice. 

5

Technical Support / Re: Aqua Hot suddenly not heating?

« Last post by Eric Maclean Co-Admin on May 03, 2026, 10:55:54 PM »

Roger
You stated that the aqua Hot burner comes on with the switch and that it runs for a little while and then and runs a purge cycle and shuts off followed by the light in the switch going out.
Are you sure that the burner actually ignites or are you just hearing the blower run while it runs through the purge cycle ,tries to ignite and run through another                 purge cycle and shuts down.
The little processor that runs the aqua Hot burner is set up to ignite using a small ignition coil and a pair of electrodes, the burner will run through a per cycle first to make sure there's nothing combustible in the combustion chamber and then it opens the fuel solenoid and runs the igniter ignition coil to ignite the burner.  if the photo cell in the burner arrangement does not see a light ie a burning flame the controller then shuts down the fuel solenoid valve and runs a purge cycle after which it turn off the lamp in the switch notifying you that the burner has failed to ignite.
 it will stay this way until the next time you turn the switch off and then back on.
The alcohol is a wonderful unit when it works but it does require regular maintenance to make sure that it works efficiently and well.
The first thing to do would be to do a full service on the burner this requires removing the burner head to access the combustion chamber and burner tube the burner tube can then be removed and cleaned along with the burner chamber itself it's common for these to get suited up which creates all sorts of problems with the burner. As part of the service it would be a good idea to replace the burner spray nozzle as these are aware item and should be done annually. Of course the new fuel filter should be installed and the ignition electrode alignment and GAP should be checked apart from that there isn't a lot to do on a servicing and like I said it should be an annual event once you become familiar with the system it isn't all that daunting the hardest part is getting the cover off to get to the burner.

There are several faults that can result in a non-ignition event or a flame out.
1) lack of spark or bad ignition coil dirty ignition electrodes or electrodes that are not gapped properly.
2) lack of fuel possibly a plugged fuel filter plugged nozzle or a bad nozzle spray pattern.
3) a photocell that is inoperative or just plain suited up so it can't see that the light of the flame.

You should be able to find the manual for your particular aqua hot model number in the coach assist library that manual will walk you through the complete service and repair of the unit.

Hope this helps
Eric

6

Technical Support / Re: Solar. Or not. Solar parts

« Last post by Eric Maclean Co-Admin on May 03, 2026, 10:37:12 PM »

Randy
It's a large solenoids you see it on the firewall under the bed the large one is the boost solenoid on one side of that blue solenoids large cable is connected to the chassis batteries on the other side of the solenoid the large cable is connected to the house batteries.
The other solenoid which is down a little lower on the firewall towards the passenger side is the infamous salesman switch solenoid this is the one that turns the House power on and off to the 12 volt accessories in the coach.

Eric

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Technical Support / Re: Solar. Or not. Solar parts

« Last post by Randy Keaveny on May 03, 2026, 03:28:57 PM »

Thx for the input. So many solenoid.   I hate to start messing with them as I know 0 about what does what.    Great idea.  But without first hand knowledge.  Kind of a shot in the dark.     Thx again.   I'll just leave it as it is. 

Randy.

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Technical Support / Re: Solar. Or not. Solar parts

« Last post by Joel Ashley on May 02, 2026, 11:16:03 PM »

There are many apps available for reducing the pixels so they are easier to email or to meet the BAC site posting guidelines limits of 300kb each or 5MB per post.  I try to keep them in the 250kb @ area.  I use an Apple Store app called “Image Compress and Resize Easily” that may not be available for Windows/Android devices.  Other apps I tried were too complex, designed for more professional use.  It takes a little practice to get the hang of it, and how it saves modified images to your photo album, but uses simple sliders to adjust down the kilobytes to under the 300kb mark.

You should review the “Guide to Resizing and Posting Photos” in the Forum Assistance (Members Only) section here.

Joel

9

Technical Support / Re: Solar. Or not. Solar parts

« Last post by Eric Maclean Co-Admin on May 02, 2026, 10:59:53 PM »

Randy
The quick answer is yes.
Beaver used three solar panels on the roof on those earlier coaches a small 15 watt panel connected to the chassis battery bank with no solar charge controller and two larger panel of about 40 watts each they are the ones connected to the charge controller you are looking at those two are connected to the house battery bank .
The wiring for both sets of panels are routed down from the roof along the passenger side of the rear cap along the edge of the bed frame forward to the charge controller.

It should be noted that Beaver did not use a charge controller for the small 15 watt panel as they believe the max 1 to 1.2 amp output would be no threat to the chassis battery bank.
And the house battery bank at 40. Watts x 2 or a total of 80 watts is only works out to just a little above 6 amps
As you can see these solar outputs are not much more than a trickle charge and where realistically only installed to maintain the batteries while the coach was on the sales lot to make up forany  parasitic draws from engine ECM transmission TCM and draws on the coach battery from propane and CO. Detectors.

Eric

10

Technical Support / Re: Aqua Hot suddenly not heating?

« Last post by Joel Ashley on May 02, 2026, 10:41:08 PM »

“ There's no Red indications on any of the system monitor lights, so I don't know if I have air in the system or if something else is going on.”

If there is no warning red lamp on the low coolant indicator on the black monitor panel in the hydronics bay, then the implication is that what Fred and I proposed may not be the issue.  But if the lamp is red, then you can jumper the top right two terminals on the panel board.  A simple paper clip may do it, but I personally would use a little more sophisticated or electrically aesthetic and secure approach.  Keep in mind that this would be only a temporary “fix”, that left in place could endanger your entire device should coolant actually become very low in the tank.  Permanent repairs should be prioritized.

Here is a link to a more detailed document you should print out and keep with your hydronics manual(s) for future reference, even if it’s not the issue this time.  Keep in mind that the illustrations therein might not exactly match your unit, and there may be other ones and online videos out there that are more specific to yours.

https://wiki.foreforums.com/_media/technical:aquahot:how_to_defeat_float_switch_-_2-2009_.pdf

-Joel