OK, assuming that you are making the resistance measurements with the black test lead touching terminal 12, check to see if you have continuity between terminal 3 and terminal 12. You should measure something close to 0 ohms between them, though I notice that you do not have a value for terminal 3 in your readings.
If not 0 ohms (or close, an ohm or two is fine) between 12 and 3, check the solder joints of the black wire from 3 to the volume pot, volume pot to headphone jack, and headphone jack to 12. That is how the two are connected.
If it is 0 then put the black lead on terminal 3 and measure the resistance from 7 to 3 and 9 to 3. That should be 3K ohms. If you are getting a wacky reading there but 12 to 3 is OK it may just be that your meter is being confused by the 100uF electrolytic caps between 6 and 7 and 9 and 10, which may be charging up off of the meter's battery.
