Fender Bassman 70

[ICOLT45]

I have a fender Bassman 70 Everything seems to work just fine, except the extension speaker output? nothing comes out when i plug into it? Can you help?

[acorkos]

is that with or without a speaker connected to the main speaker output jack?

[Bruce / Mission Amps]

I have a fender Bassman 70 Everything seems to work just fine, except the extension speaker output? nothing comes out when i plug into it? Can you help?

As acorkos is pointing out... the normal speaker jack is a three lug shorting or switch jack.
With nothing plugged in, the output is shorted to ground.
You can not use the other, aux extension "mono/unswitched jack, which only has two lugs, without having an open 1/4" phone plug inserted into the normal used speaker jack, thusly opening it's shorting switch.
Pretty wordy, huh?