Wiring Delco 2700ETR radio

[57Tom]

Hi, simple question on original GM Delco 2700ETR radio. There are two wires hardwired to unit [orange and brown] besides the three plugs, two for speakers and one for power, ground, and dash lights. I know the orange is for constant power for memory but the Brown is for ? This radio is being installed in my 79 stepper that had no radio so noting to go by, besides the 2700ETR is a later model radio. Also, when did GM use this radio? It is a direct fit for earlier holes. Thanks, Tom.

[heavychevy91]

iirc brown is the dimmer wire...

[Grover 1]

This radio is a direct fit for the shaft mount radios.  I don't know what years from start to finish but my 1986 came with one.  They are nice units, mine still works although the LED readout works when it wants to.  I think the problem is cold solder joints, so it's an easy fix.