2016 Axis 25.2 - BIRD / Trombetta resolved

[YoungclassA]

Just a quick thank you post - This is our first RV - I'm having a mid-life crisis and see the window closing with ours kids. We only have four to five more years before they won't want to hang our with us anymore. I've had travel trailers, boats, SxS, etc, but never a RV. We were blessed with a 2016 25.2, absolutely love it and working on fixing a few things. Top of the list was the chassis battery dying when plugged into shore power. I read, on this forum, about the BIRD and trombetta system. My setup was wired incorrectly from the factory because the PO would keep a batter charger on the chassis battery. The factory had spliced the red wire, from the bird, into a yellow wire that ran to the trombetta post - chassis side. Not coach battery side. Therefore the trombetta would never close on shore power and the chassis battery would eventually die. I swapped posts and just checked on it; The chassis battery was at 12.9v, opposed to 12.0 last night. Thanks forum, hope to see you all on the road.

[Mr Sunshine]

Welcome! We bought a new 2016 25.2 in 2015 and enjoyed a lot of miles and nights in it. Just traded it last fall for a Hurricane.

If you haven't already done it, download Ed Felker's excellent crowd-sourced manual for Vegas and Axis from the forum under Tech Topics. There are some great threads about modifications here on the forum, too

[shspector]

I've had the same issue since day one (Jan 2016) when you say you switched posts what exactly do you mean? when looking at the trombetta from outside, on the right large post is a large red cable & a small yellow wire. On the left large post is only a large red cable. Then a white small wire in the rear & a small 2 color in the front. What did you switch?
thx

[VBFLgirl]

any chance you could post a pic of the wiring you have now? I think I have the same problem but would like to verify the wires 1st


thanks so much!

[Mark54]

Originally Posted by YoungclassA

Just a quick thank you post - This is our first RV - I'm having a mid-life crisis and see the window closing with ours kids. We only have four to five more years before they won't want to hang our with us anymore. I've had travel trailers, boats, SxS, etc, but never a RV. We were blessed with a 2016 25.2, absolutely love it and working on fixing a few things. Top of the list was the chassis battery dying when plugged into shore power. I read, on this forum, about the BIRD and trombetta system. My setup was wired incorrectly from the factory because the PO would keep a batter charger on the chassis battery. The factory had spliced the red wire, from the bird, into a yellow wire that ran to the trombetta post - chassis side. Not coach battery side. Therefore the trombetta would never close on shore power and the chassis battery would eventually die. I swapped posts and just checked on it; The chassis battery was at 12.9v, opposed to 12.0 last night. Thanks forum, hope to see you all on the road.

Not sure this will help, but after I moved my electrics and batteries up inside, I also added a NOCO hardwire 2A trickle charger and wired to the Tellaro's trombetta so my chassis battery would stay alive. It would die in less than 2 weeks otherwise. So when plugged into shoreline at home, I can just switch on and it send a trickle charge to the chassis battery. I only use when stored for longer than 3-4 days, or between trips. Phantom drain on the chassis battery is pretty high in the Promaster.
I removed the outlet on the outside and made it a switchbox, added a dedicated outlet inside the new compartment and plugged the NOCO into that. Wired to battery B+ side (lower post in pic- verified by testing for voltage against ground) of trombetta and B- ground buss bar.
Large wire (last pic) on top of Trombetta goes to B+ buss bar for e-start function.

Works like a charm to keep chassis battery fully charged.
When winterized and house batteries removed, I have another NOCO 2A charger that I connect to the jumper posts and plug into a 20A outlet nearby, since I am not on shoreline power then. Too cold in VT to store batteries, even at 50%. The plan for that one is to add a 20A Marinco plug somewhere on the outer trim, and mount the Noco inside and hardwire to the jumper posts, so all I have to do is plug in an extension cord.

I did that on my utility tractor as well- handy to just plug in like the old days when I had frost plug heaters on my diesel and gas cars.

[shspector]

Sorry, I sold the motorhome 2 yrs ago............but if you search the thread you might find a picture from the individual that showed me........summer/fall of 2022........good luck