08 Patriot Thunder Chassis Batteries Discharging

[Michael Lasseter]

We replaced house and chassis batteries in February of this year.  After about three to four days on 50 amp shore power we have been getting a "low battery" notice on the dash.  In about seven days the chassis batteries are at 12.3 V and I get a "engine com failure" notice and the engine won't crank over.  I found that the shore setting on my Magnum AGS was set at 30 amps and changed it to the 50 amp setting, which did not seem to help.  I also re-cleaned connections on all batteries.

I just checked voltage in and out of the Big Boy Solenoid and found 13.3 V going in and 12.7 V coming out, which is what I read at the chassis batteries.  Two days ago I charged the chassis batteries to 13.3 V to matched what I see on the house batteries when they float charge.  I'm hoping that I have finally found my problem.

I can't find the thread where another member said that any voltage drop across the Big Boy solenoid meant it was bad because it's a pass through solenoid.  Another thread I can't find, talked about dis-assembling the solenoid to clean the contacts.  Any help would be appreciated, this problem has been haunting us since we purchased the coach in February.

Michael

[Steve Huber Co-Admin]

Michael,
It may be that the BIRD system is malfunctioning and not closing the Big Boy solenoid.

Gerald Farris' response to a recent similar problem:
"When your charging voltage reaches the programed threshold, the "BIRD" controller should send a 12 volt pulse to the "Big Boy" solenoid to engage it and then reduce the voltage to it the 6 to 8 volt range to keep it engaged. The voltage reduction is necessary because the "Big Boy" is not a continuous duty solenoid and it will overheat and fail if you use 12 volts to keep it engaged, but it will stay engaged with the reduced voltage after the initial 12 volt pulse without failing."

Steve

[Michael Lasseter]

Steve,

Thank you for the response.  What Gerald said makes sense.  I did find a small terminal on the Big Boy that has 12.4-12.5 V.  I have been unable to find the BIRD controller in the Run Box, located in the top right corner of my engine compartment, or either battery compartment.  I went to BIRDS website to see what the relay looks like.  I could use any one's suggestions about where else I should look for the relay. 

Michael

[Bryan Beamon]

Michael, the bird on our 07 Contessa is located on the door to access the Big Boy battery isolator. You can pull up on the Intellitec's Web site a picture of the bird controller for verification. You also can use your battery boost switch to engage the Big Boy to charge your chassis batteries if the bird did not function properly.

[Steve Huber Co-Admin]

Michael,
Mine is located on the door of the rear electrical bay. See picture.
Steve

[Joel Ashley]

Mine looks just like the one in Steve’s photo, Michael;  on the inside of the door to the large main fuses and Big Boy cabinet.  If you’ve obviously seen the BBoy and not the BIRD, your rig must be very different.

Joel

[Michael Lasseter]

Joel/Steve

Thanks for the photos and information.  I don't know if the 45' coaches were significantly different or if a couple or years made the difference but the BIRD location remains a mystery.  I hate to say it but I'm going to take a short cut and install an Amp-L-Start and hope that someone at the Farmington, NM Rally can help me locate the BIRD.

Michael

[Steve Huber Co-Admin]

Michael,
Interesting. I see the BIRD module in 08 and 09 Contessa documentation but can't find it in an 07 Patriot manual. Maybe they went to a different system. Hopefully an 07-09 Patriot or Marquis owner will chime in on this.
Steve

[Paul Aronson]

I have a 2007 Patriot Thunder. Had what sounds like a similar issue. Wound up replacing the Big Boy relay and it fixed my problem.
The Big Boy relay should just pass through voltage as others have stated. If there is more than about a 0.5 volt drop across the relay it is probably bad or needs cleaning inside.
Relay in in the rear run box behind the black cover.
Will try to post pic of my failed Big Boy

[Paul Aronson]

Big Boy picture