Power off the amp.
Disconnect the subwoofer.
Plug the leads into the DVM if required.
Insert the red lead from the DVM into the positive speaker terminal.
Insert the black lead from the DVM into the negative speaker terminal.
Turn on the DVM by moving the selector to AC voltage.
Turn on the amplifier and set the radio to a low-to-medium listening level.
Read the AC voltage on the screen.
Is it higher than 0.00?
If not, slowly increase the gain control to try to increase the voltage.
Does it increase to greater than 0.00?
If so, the amp is good.
If not, turn off the radio and amp, and install your ipod to the amp.
Turn on the iPod.
Turn on your radio (this will turn on the amp if wired properly, but leave the radio volume down, and turn up the iPod volume).
Read the AC voltage on the screen.
Is it higher than 0.00?
If not, slowly increase the gain control to try to increase the voltage.
Does it increase to greater than 0.00?
If so, the amp is good.
If not, the amp is bad.
GAWD, I HATE flowcharts.
If you distrust the DVM for any reason, using the AC voltage setting, insert the two prongs into the two blades of a working wall outlet, and you should see 110V or so.
This confirms working of the DVM.