Engine batteries not charging

[tomgauger]

Go to Harbor Freight and buy the small 12v trickle charger for a little over $20. It can be mounted inside the high amp cage. Run a 110v cord from the outlet where the block heater plugs in. Connect the DC leads to the chassi positive terminal nearby and the black lead to ground.Works perfectly.

[twinboat]

Originally Posted by tomgauger

Go to Harbor Freight and buy the small 12v trickle charger for a little over $20. It can be mounted inside the high amp cage. Run a 110v cord from the outlet where the block heater plugs in. Connect the DC leads to the chassi positive terminal nearby and the black lead to ground.Works perfectly.

If this is a suggestion to work around the bad battery tempture sensor, the sensor controls the house battery charging too.

If the sensor is bad, they don't get the proper charge either.

[kenwyatt]

Ok this is what I am seeing as of this morning.

1) New BTM unplugged, house float charging at 13.3 to 13.4
2) Chassis down to 12.39, no Big Boy engaged
3) Did not start the engine but pushed the “boost” switch.
4) The Big Boy latched in and both banks are in float charge at 13.3

All above was at 08:00 this morning and they are both still charging at 12:00. Haven’t started the engine to see if the BB latches in but fairly sure it will. Haven’t dug down to the B.I.R.D to start checking inputs and loose wires yet. Next step. Any input from anyone whose had similar issues

[kenwyatt]

Update,
Not 100% sure all the issue is solved but found there is a small CB (15 amp) labeled B.I.R.D relay on the main DC bus located above the relay. It was tripped. Reset but the BB was latched so no changes. Believe that was it as I have had all of the batteries out recently doing a complete rebuild and replacement of the trays. May have upset it. Will shut everything down and kill both disconnects and bring everything up to check but at this point I think everything is back to normal or as close as it gets. Thanks for everyone’s input as it all helped with the troubleshooting and understanding the operation of it. Will post if this doesn’t work and I have to dig any deeper.

[kenwyatt]

Last update,promise. The chassis batteries charger for 2 days so I shut everything down to include the disconnect switches. Heard the BB relay drop out and everything stabilized at about 12 volts. Waited a bit and brought everything back up in sequencer. The charger went to 14.1 but more importantly the BB relay closed as it should and is charging both banks. Thanks to everybody for the input but I am calling in the dogs and this hunt is over. On to the next adventure

[megehrs]

Originally Posted by kenwyatt

Will do more research tomorrow and try to get a part number of the B.I.R.D but from what I’ve found it looks like the cut in is at least 13.3 so the 13.2 I am seeing may be the problem. Will post when I get a little more information

I think you will just have to crawl underneath and thread it 25 ft. I did mine. Did not need to jack the rig. I just raised the air bags. There is a surprising amount of room over the rear axle and tag. No so much under the rest. I drilled an access hole in front of rear axle to get the wire inside the compartments. Was not nearly as difficult or dangerous after that. Bring a large handful of zip ties when you go underneath. Work from rear battery compartment forward. Follow existing wire bundles. Mine took about an hour to install. Did not chase the old one. Just cut it off and leave it. You will get plenty dirty. Good luck