737 ng warning lights
 

Does anyone know where the warning lights get their power from on the 737ng? Do they all get power off the same bus or do they differ?
Thanks
Jon

According to one NG Wiring Schematic manual, Jon, the lights are supplied with power from either Battery Bus Section 3 or 28V DC Bus 1 section 2. The systems themselves provide an earth to activate the light. I don't believe Battery Bus Section 3 is hot. You will need the Battery Switch to be on.

I think you would need to look at each system to see if the earth was supplied to the lights with or without other sources of power. You might need a powered circuit to close a relay of some description to give you the earth, you might not.

Hope this helps?

Regards.
Q.