Gemini Coach Batteries Non-Op - Debugged w No Luck

[HarryM]

Javelin, thank-you for all your your effort towards solving this electrical mystery, I really appreciate it.
Today I held down the generator "Start" button and after three seconds the genpac started after a short crank. Odd though, because it used to crank over after holding the start button for one second. I guess we're all getting old...Anyway, generator solved.
I'll trying the Use/Store/latching relay with the generator running and see if this path for some strange reason causes the house circuit to come alive.
Otherwise, I'm going to tinker a little more today. Thanks again :-)

[HarryM]

javelin, thank-you for your continued intel. I much appreciate it.
Your latching relay wiring diagram was the key to solving this issue as it led us to locate a second solenoid latching relay in the rear of the converter cabinet. This relay was burned out.
After having had no luck in solving the issue, I decided to return the original Trombetta relay to the under-coach position, and install the new BD latching relay into position in the back of the converter cabinet. The house batteries now function as intended.
LESSON LEARNED
Contrary to numerous blogs where fellow RV'ers have replaced failed Trombetta relays with the BD latching relay (photos prev attached), this will not work on the Thor Mercedes or Ford chassis Class B RUV. The reason is beyond my pay grade.
javelin, thank-you! Your wiring diagram helped lead to the failed part, which btw is not mentioned on any of the Thor wiring schematics provided by Thor technical support. And, you were correct in that now I have a pretty good understanding of the entire coach battery wiring system.

[javelin]

Well HarryH a hearty congrats to you ( and TDW) for not giving up on finding your problem. You are well on the way to knowing where battery control system devices are located (usually the worst part) on your coach and how they are supposed to operate together. That is a huge win for you to address any future problems that you may have down the road. Lets hope you have few future problems; and I hope that others reading this exchange will also learn some electrical things and to never give up.

[javelin]

Sorry HarryM......not H

[GrannyMML]

I seem to have the same issue in my Gemini 24TF. Shore power operates, except for the step and the batteries are not charging. No ATS sound when the house disconnect is pushed. Does anyone have any info on the 24TF? The ATS and controller are under the bed; next to the water tank.

[TurnerFam]

Here's some basic info to help in identifying the issue:

- RV steps generally are powered by the Chassis battery(s), not shore power, and they are also tied into the ignition, since the steps must come in when the vehicle is moving.

- If the batteries are not charging, while on Shore Power, then you have lost the 120v incoming power to the Converter. Or, the same if you have an integrated Inverter/Charger.

- the ATS(automatic transfer switch), which is a switch between the Shore Power and the Generator power, is not effected, or connected, to the USE/STORE 'house disconnect' switch.
The ATS is working properly if you have Shore Power.

-the USE/STORE 'disconnect' switch is ONLY for the 12v system, otherwise for disconnecting the Fuse Panel, even though 'some' 12v devices may StILL continue to draw from the HOUSE Battery bank, such as C02 or Smoke detectors, etc.
Yes, it 'should' make an audible 'click' or 'clunk' when switched, but it's not always as audible on some RVs as on others. Turn on any interior LIGHT, then use the USE/STORE switch to get a VISUAL confirmation of whether it's operating properly.

[16ACE27]

Originally Posted by turnerfam

here's some basic info to help in identifying the issue:

- rv steps generally are powered by the chassis battery(s), not shore power, and they are also tied into the ignition, since the steps must come in when the vehicle is moving.

- if the batteries are not charging, while on shore power, then you have lost the 120v incoming power to the converter. Or, the same if you have an integrated inverter/charger.

- the ats(automatic transfer switch), which is a switch between the shore power and the generator power, is not effected, or connected, to the use/store 'house disconnect' switch.
The ats is working properly if you have shore power.

-the use/store 'disconnect' switch is only for the 12v system, otherwise for disconnecting the fuse panel, even though 'some' 12v devices may still continue to draw from the house battery bank, such as c02 or smoke detectors, etc.
Yes, it 'should' make an audible 'click' or 'clunk' when switched, but it's not always as audible on some rvs as on others. with sp disconnected and the generator not running, turn on any interior light, then use the use/store switch to get a visual confirmation of whether it's operating properly.

FTFY

EDIT: and there goes the uppercase ==> lowerscase when quoting and bolding bug again. I edited the FTFY back to UC and it stuck this time but everything in the quote except for "Yes" went to LC.