Monaco Battery Boost Switch

[palehorse89]

Originally Posted by EDZ SIG

The chassis batteries seem to be reading 12.5-12.6 volts using my meter then go down after an unsuccessful attempt to start the engine. I had to run the gen for 1.5 Hours the last time before getting the engine started. That is not an acceptable delay when I'm anxious to get started on a trip. While in storage, there is no shore power available to connect a battery charger. Interesting to note that the battery gauge on the dash read only 11-11.5 volts when I first attempted to start the engine and is a major clue to me I'm going to have a problem. Unfortunately, I didn't take a reading on the house batteries but my impression is they didn't drain very much while the Sig was in storage. That's why I thought jumping the chassis and house batteries might be effective in getting me on my way is the battery boost switch was not functioning properly.

You can give it a try, I don't see where it will hurt a thing, other than the stress on the engines alternator when it starts, if it does. Sounds like all of the batteries are run down though
The converters/chargers are made to charge batteries, the engines alternator is designed to maintain them. Best advice in your situation, is to get them up to full charge, and un-hook the negative terminals on both house and chassis batteries till you figure out what is killing them.

[Randyman1]

You could always put a disconnect on the ground for the chassis batteries to really unhook them if there is a parasitic draw. Couple other things, have you ever cleaned or replace the BIRD unit in the rear run box? That is your boost solenoid as well. Then the really big question is have you replaced your starter yet? I have the big engine as well and a month ago finally switched to the Denso gear reduction starter that I learned about here. WOW!!!! What a difference in the way that it cranks over. You might have enough battery if your starter wasn't dragging or extremely underpowered for cranking that big engine. That's my 2 cents worth. Randy

[EDZ SIG]

Originally Posted by Randyman1

You could always put a disconnect on the ground for the chassis batteries to really unhook them if there is a parasitic draw. Couple other things, have you ever cleaned or replace the BIRD unit in the rear run box? That is your boost solenoid as well. Then the really big question is have you replaced your starter yet? I have the big engine as well and a month ago finally switched to the Denso gear reduction starter that I learned about here. WOW!!!! What a difference in the way that it cranks over. You might have enough battery if your starter wasn't dragging or extremely underpowered for cranking that big engine. That's my 2 cents worth. Randy

Thanks everyone for your input. I think I'm on information overload. I've only had the 2003 Signature for a couple of years so haven't done any major service work on it and don't know all the former history.
It appears I can jump start the chassis and house batteries using cables until I find out if the battery boost is currently working. ( I don't think it is.)
Somehow installing another disconnect switch on the chassis batteries ( in addition to the chassis disconnect already there ) may help with the phantom drain on the batteries while in storage.
I know knothing about BIRD switches and the heater someone mentioned on the ISX engine to heat air during the starting procedure?). I don't think I'll look at replacing the starter on the Sig which seems to be a bit drastic at this stage.
Anyway, thanks everyone for your input! Hopefully I'll have several years to figure this all out.

[Randyman1]

Quote: I know nothing about BIRD switches and the heater someone mentioned on the ISX engine to heat air during the starting procedure?). I don't think I'll look at replacing the starter on the Sig which seems to be a bit drastic at this stage.
Anyway, thanks everyone for your input! Hopefully I'll have several years to figure this all out.

I know it can all seem overwhelming at times! Two really important things: The BIRD solenoid is found in your rear run box and says Big Boy on it. These have to be replaced or cleaned and the age of your coach dictates that should be done and would solve both jump starting and charging issues you are having. The second one is these ISX engines have inadequate starters, period. Another known issue and the sooner you replace the sooner you'll be starting. Do your research on this forum and you will find this to be true. Lastly there is no pre heat grid on the ISX. Randy

[palehorse89]

Originally Posted by Randyman1

Quote: I know nothing about BIRD switches and the heater someone mentioned on the ISX engine to heat air during the starting procedure?). I don't think I'll look at replacing the starter on the Sig which seems to be a bit drastic at this stage.
Anyway, thanks everyone for your input! Hopefully I'll have several years to figure this all out.

I know it can all seem overwhelming at times! Two really important things: The BIRD solenoid is found in your rear run box and says Big Boy on it. These have to be replaced or cleaned and the age of your coach dictates that should be done and would solve both jump starting and charging issues you are having. The second one is these ISX engines have inadequate starters, period. Another known issue and the sooner you replace the sooner you'll be starting. Do your research on this forum and you will find this to be true. Lastly there is no pre heat grid on the ISX. Randy

Hi Randy, things are getting mixed up a bit here I am thinking............
The "Big Boy" solenoid switch is for the Battery boost button to join the house and chassis batteries together for starting.
The BIRD system controls how and what charges the batteries.........
http://www.intellitec.com/assets/pdf...-00839-100.pdf
And to add to this, the newer Coach's have a IRD system!
http://www.intellitec.com/assets/pdf...-00629-120.pdf

[Randyman1]

Originally Posted by palehorse89

Hi Randy, things are getting mixed up a bit here I am thinking............
The "Big Boy" solenoid switch is for the Battery boost button to join the house and chassis batteries together for starting.
The BIRD system controls how and what charges the batteries.........
http://www.intellitec.com/assets/pdf...-00839-100.pdf
And to add to this, the newer Coach's have a IRD system!
http://www.intellitec.com/assets/pdf...-00629-120.pdf

Right Palehorse, I meant to say Big Boy Solenoid is found in the rear run box and the BIRD on mine is just beside the batteries, got my B's confused and it also engages both banks for charging. Sorry about the confusion. When I bought my coach it would charge both banks (coach & house) when plugged in but wouldn't charge the house batteries off of the alternator when running down the road. Big Boy solenoid was toast, replaced it and got both banks of batteries charging whether plugged in or driving. Also the boost switch worked too. I understood it to be that the BIRD is the brains that tells the Big Boy what to do. I thought I had it right. Randy

[palehorse89]

Originally Posted by Randyman1

Right Palehorse, I meant to say Big Boy Solenoid is found in the rear run box and the BIRD on mine is just beside the batteries, got my B's confused and it also engages both banks for charging. Sorry about the confusion. When I bought my coach it would charge both banks (coach & house) when plugged in but wouldn't charge the house batteries off of the alternator when running down the road. Big Boy solenoid was toast, replaced it and got both banks of batteries charging whether plugged in or driving. Also the boost switch worked too. I understood it to be that the BIRD is the brains that tells the Big Boy what to do. I thought I had it right. Randy

....post # 7 here http://www.irv2.com/forums/f84/hot-solenoids-88792.html
Sorry if I add to the confusion here........
You are right!

[EDZ SIG]

I easily found the Big Boy solenoid located in the motor compartment of my Sig. Someone had told me earlier that if it was warm to the touch when I was connected to shore power, it was doing it's job charging the chassis batteries. I haven't looked for the Bi-Directional Isolator Relay (BIRD) if I have one in my 2003 Monaco Sig with the 525 HP ISX engine. I printed out the cut-sheet but don't recall seeing anything that looked like that. Are you guys saying if the Big Boy is a "Bad Big Boy" that could be the source of my Battery Booster switch failing to connect the chassis and house batteries during my attempt to start a cold engine?

[Randyman1]

Originally Posted by EDZ SIG

I easily found the Big Boy solenoid located in the motor compartment of my Sig. Someone had told me earlier that if it was warm to the touch when I was connected to shore power, it was doing it's job charging the chassis batteries. I haven't looked for the Bi-Directional Isolator Relay (BIRD) if I have one in my 2003 Monaco Sig with the 525 HP ISX engine. I printed out the cut-sheet but don't recall seeing anything that looked like that. Are you guys saying if the Big Boy is a "Bad Big Boy" that could be the source of my Battery Booster switch failing to connect the chassis and house batteries during my attempt to start a cold engine?

Yes, that Big Boy solenoid is what energizes and hooks your banks of batteries together when you push the boost switch. The way I found mine bad was the part about not charging the house batteries when going down the road, I had tried the boost once before changing that and it didn't seem to do anything. My BIRD brain is located aft of the battery compartment on the side wall of the battery compartment. About a 4x4 square box. Yours might not have one, but I would think being a Sig that it might, just might be located elsewhere. Mike Canter or Steve Ownby might chime in as they have closer to your year Sigs. And just FYI my Big Boy was warm/hot to the touch when it was not doing all that it should be doing.

[Steve Ownby]

Originally Posted by EDZ SIG

I easily found the Big Boy solenoid located in the motor compartment of my Sig. Someone had told me earlier that if it was warm to the touch when I was connected to shore power, it was doing it's job charging the chassis batteries. I haven't looked for the Bi-Directional Isolator Relay (BIRD) if I have one in my 2003 Monaco Sig with the 525 HP ISX engine. I printed out the cut-sheet but don't recall seeing anything that looked like that. Are you guys saying if the Big Boy is a "Bad Big Boy" that could be the source of my Battery Booster switch failing to connect the chassis and house batteries during my attempt to start a cold engine?

In your coach the BIRD function is performed by the Big Boy solenoid which performs as the isolator and the combiner. The BB is controlled by a circuit board over on the far right of the rear run box where the BB lives. If I remember correctly it's the second circuit board from the top. It has a couple of yellow buttons on it. It has a connector on the top and the right edge of the board. There are several failure modes of the circuit board and it's possible for some functions to work & others not. The BB can be warm but have to much internal resistance to get an adequate charge. If there is around 13.3 VDC at both big lugs on the BB and they are within a couple of tenths of each other, then the BB itself is ok. With the engine off have someone hold the "boost" switch. You should hear a clunk or two and voltage should equalize between the big lugs.

If you continue to have trouble, call Monaco tech support while at the coach and they can step you through troubleshooting. Mike Canter wrote up the procedure to open up the BB and clean up the contacts. It's not particularly complicated but a couple of steps are a little tricky.

[Randyman1]

HI Steve, I found you had posted this article for another person having trouble with their BB. Really spells it out and might help those on this feed having trouble.

Here is a write up by a Monaco owner who is very knowledgeable about the Intellitec Big Boy BIRD system.

The Big Boy Relay is controlled by Bird Relay which is located in the RRB. It is located on the right side and is the third circuit board from the top. There is a Green LED-(ISO Relay On)-third from the top on the board that should be Illuminated and the Big Boy Relay should have a low humm and be hot to touch when working properly.

When you disconnect from shore power and the generator is not running, the Green LED should be out. The Big Boy Relay will drop out of the circuit when the dc voltage drops to 12.5 to 12.8 vdc when measured at the Battery side of the Big Boy Relay.

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.

On the BB Solenoid you should be seeing 12.8+ vdc on the chassis side battery post-(left side) and 13.0+ vdc on the house battery side post-(right side). A differential of .3 to .6 vdc between these two posts is normal.

If your Inverter is set up correctly and the Bird relay is working-(green light on) the Inverter through the BIRD Relay and the BB will charge the Coach Batteries first and then the Chassis batteries and when all the Batteries are fully charged the Inverter will go into float charge. When plugged into Shore Power or with the Genset running the Green LED will be Lit on the BIRD Relay Circuit Board, If not I would venture to guess that the circuit board is failing or has failed. The relay above the eight pin connector on the BIRD circuit board controls the Big Boy Relay, it could be failing.

[EDZ SIG]

Great information! I'll have to look around more in my RRB ( I just learned that term - Rear Run Box ) and find these components and get familiar with them. You answered one of my other big questions about the house batteries being charged first and then the chassis batteries being charged second. The Monaco logic fails me as I would think while travelling that starting the engine, returning the MH to travel height from the levelled position, bringing in the slides, etc. should be a higher priority than charging the house batteries. After all, if the chassis batteries are low and I have to run the generator to charge them up to start the engine and get back on the road, does that mean I'm waiting for the house batteries to charge first? Makes no sense to me.

[JohnBoyToo]

I am of the opinion you should either disconnect your batteries when in storage or at least put a blade switch in there to isolate them...

Our last "high end" 5er had so much parasitic draw that it would deplete the three batteries in a day or two - even WITH the disconnects turned off !

[Steve Ownby]

Originally Posted by EDZ SIG

Great information! I'll have to look around more in my RRB ( I just learned that term - Rear Run Box ) and find these components and get familiar with them. You answered one of my other big questions about the house batteries being charged first and then the chassis batteries being charged second. The Monaco logic fails me as I would think while travelling that starting the engine, returning the MH to travel height from the levelled position, bringing in the slides, etc. should be a higher priority than charging the house batteries. After all, if the chassis batteries are low and I have to run the generator to charge them up to start the engine and get back on the road, does that mean I'm waiting for the house batteries to charge first? Makes no sense to me.

It's been a while since I've really looked at the BIRD function, but I believe, when the main engine is running and the alternator is charging, the chassis batteries are charged first and then when the BB is energized the charge current flow is from the chassis to the house.