dcc on board no sound

[bluegmc]

My grandson and I have a bachmann EMD GP7 it has dcc on board no sound can this be converted to dcc with sound just by changing the decoder and adding a speaker?   

[jward]

my gp7 has a milled out area in the fuel tank area to accept a speaker. so although I have not tried it, it should be an easy conversion to sound.

[Hunt]

Click Here for detail instructions.

[Bill1462]

I have a GG1 Pennsylvania Railroad DDC engine. It makes the sound with my analog controller, but makes no sound at all with the DDC unit I have. The headlights does not even work. Both the engine and the controller are Bachmann products. Why won't they work together? The DCC unit is an "E-Z Command Control Center" Item # 44901.