Had siding done, now have low and no voltage to 2nd floor

I had siding done recently and have basically lost electricity to my second floor. The contractor paid an electrician to come out and they thought there was a loose wire in a junction box, and that would be on me to pay for repairs. After paying for siding I can't really pay for electrical work. I went in the attic and found no junction boxes. This is an old two wire knob and tube setup by the way. For all the connections and splices I could find (about positive found it all) everything seems well connected. Oddly enough, light switches have anywhere from 4-25 volts but outlets are reading zero. It looks like the entire second floor is fed off of one hot and one neutral wire with each running up opposite corners on the back of the house. Any ideas why I get low voltage from switches and nothing from outlets when they run off the same circuit? Any thoughts on what else I should be looking for? Thanks