Battery Cross Connection

[Walter Pigeon]

2011 Georgetown, battery disconnect does NOT cut all power, BCC still has power, we suspect the battery cross connection (emergency start) relay is stuck, you don't hear any click when the "boost" button is pushed... is there somewhere to check voltage to determine if that relay is indeed faulty? I believe from some diagrams I have seen the suspect relay is inside the BBC but i hesitate to open it if there is voltage there

[bubbles]

Are you plugged into shore power? If not, what is still powered? How do you know the BCC still has power and from where are you measuring this if so?

[Walter Pigeon]

Originally Posted by bubbles

Are you plugged into shore power? If not, what is still powered? How do you know the BCC still has power and from where are you measuring this if so?

Shore power is disconnected... disconnected the house batteries and still have power to the propane cutoff and the carbon monoxide detector

[bubbles]

Originally Posted by Walter Pigeon

Shore power is disconnected... disconnected the house batteries and still have power to the propane cutoff and the carbon monoxide detector

That's because they (both the same control) are connected directly to the batteries. There are probably several, inline fused, items connected directly to the batteries that are not disconnected with the disconnect switch. The awning/steps/LP detector/slides, etc.. The propane cutoff/detector is a 5amp inline fuse and it can be relocated from the batteries to the top left stud on the side of the BCC and it will be disconnected with the battery disconnect switch.

Additional; the BCC top left stud is the upper stud on the outside on the right looking at the front removable panel of the BCC. Install it where this view indicates. Stud #1.

[bubbles]

Forgot to mention that, I believe, for battery boost to function the coach batteries must not be disconnected. I believe power for the boost switch comes from the not disconnected side of the disconnect solenoid via a fuse in the BCC to the switch in the dash and when the switch is actuated sends that power back to a fuse in the BCC to the interconnect solenoid.

[Walter Pigeon]

Originally Posted by bubbles

Forgot to mention that, I believe, for battery boost to function the coach batteries must not be disconnected. I believe power for the boost switch comes from the not disconnected side of the disconnect solenoid via a fuse in the BCC to the switch in the dash and when the switch is actuated sends that power back to a fuse in the BCC to the interconnect solenoid.

Found a burned out/ melted diode D2 I the power distribution box under drivers position, pulled out the pieces and now the cross connect solenoid works when the battery boost switch is activated... wth??

[bubbles]

In my owners manual for the F53 motorhome chassis those diodes are not used.

[bubbles]

Should have said in some F53 motorhome chassis the diodes are not used. In my 2012 GT378 they are for the "brake transmission shift interlock" (BTSI).