Jim,
Circling back here to update documentation after our phone conversation of yesterday evening. The tests you performed may have pointed to a failed disconnect latching relay. (see the italicized quotation from my e-mail below...) Attached below is the PDF document from Intelletec on their relay and the schematics of how they are used in coaches -- page 8 of the manual is the schematics we were discussing. I am also including text of my e-mail to you this morning, where I pointed out how I overlooked some important items on our simple testing last night...so the issue may still be in the switch itself or in the wiring.
Jim and Wayne,
I overlooked an important detail during last evening’s call that may mean the relay is OK and the wiring is at fault. I am re-attaching the document from Intelletec and will highlight some information here as well.
To operate the latching relay BOTH the “I” and the “S” terminals must have a connection through the rocker switch. We did not do this last evening… To latch ON, the I terminl needs +12 volts and AT THE SAME TIME the S terminal needs a ground connection. To latch the relay OFF, the I terminal needs a ground connection while simultaneously the S terminal needs a +12 volt connection. The momentary nature of the rocker switch ensures that the relay coil is not powered long term in either the ON or the OFF latched state.
Sorry for this oversight – it may still be a bad switch or a wiring issue (it also could still be a bad relay, but further testing will need to involve connections to BOTH small stud connections at the same time as described above…) I should have thought to test the working latching relay, the chassis disconnect, last night as well -- and that would have pointed out the error of my suggested test method. Here is the text from the Intelletec document which I have highlighted to emphasize my error of last evening:
THE RELAY -
The Battery Disconnect Relay is a mechanically latching switch that operates by the momentary application
of battery voltage to the coil terminals in one direction for latching (closed) or the other direction for
unlatching (open).
To close the relay, +12 volts is applied to the “I” terminal and ground to the “S” terminal of the relay. When
this is done, the plunger is pulled into the coil and the contacts are connected. While this happens, the rod
magnet suspended above the plunger is attracted (opposite poles attract) to the top of the plunger by the
magnetic field. See FIGURE 1
When the voltage is removed from the coil, the plunger gets pushed upward by the return spring, but
cannot move because the rod magnet is in the way. See FIGURE 2
To open the relay, +12 volts is applied to the “S” terminal and ground on the “I” terminal. When this is
done, the plunger is again pulled into the coil. However, since the magnetic polarity of the coil is reversed,
the rod magnet is repelled (like poles oppose), and swings out of the way. See FIGURE 3
Sorry for all the confusion, hope this helps isolate the real failure mode and components involved.
Chuck
Also, for those following this thread that might need to source such a part, here is the link that I e-mailed you yesterday...
https://www.rvpartscenter.com/shop-b...055-000-detail
Chuck