Dme 506/413 gauge install question

[BingM3]

I have an S50 engine in my E30M3 and am trying to install an AIR FUEL ratio gauge, does anyone know what wiring color in the 506 DME is sending signal to the oxygen sensor?

I plan to tap the gauge wiring to it.

Thanks

[SpecM]

I have an S50 engine in my E30M3 and am trying to install an AIR FUEL ratio gauge, does anyone know what wiring color in the 506 DME is sending signal to the oxygen sensor?

I plan to tap the gauge wiring to it.

Thanks

-wouldn't you want to tap the signal going BACK to the DME?