type 44 speaker impedance?

[Cody Forbes]

Start by jiggling the switch back and forth a few times while the radio is 
on and playing music. If you get sound on and off flickering then you are 
definately going up the right alley. Then go on to un-plugging it and using 
jumper wires (or a paperclip in a pinch) to by-pass it and see if this gets 
you rear sound. Oh, to get to the plug you need to pop the whole thing out 
of the deck. Just pull up on the front edge and it'll pop right out.