You can easily check if the emergency start switch works without disconnecting anything. If you have the BIRD/ Trombetta setup, test the voltage at the two poles of the Trombetta. On mine the right pole is the chassis battery. The voltages should be different. Now have someone push the emergency start and measure the voltage on the chassis battery again. If the emergency start button is working, the voltage will increase (if the chassis battery is below the charge of the house) batteries. The emergency switch is hooking the two battery systems together. If you do not have the BIRD/Trombetta setup, you can do the same thing by measuring the voltage at the chassis batter and coach batteries, have someone push the emergency start switch and see if the voltage on the house battery increases (again, if the chassis battery is below the charge of the house batteries.
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