ignition

Back on the '62 Lancer. I have 12.5 at batt., same in and out bulkhead, cleaned bulkhead terminals best I can. The brown wire at ballast in start reads 9.5 v. Same v. inside under dash at the inside of bulkhead.
I have traced voltage as thus: Replaced the ingnition switch, and checked v. there. At the terminals of the switch I have 12.5 v. there at hot black wire terminal. AT switch .WITH ign. on and checking at post for IGN.2 ( key on ign.1 spot) it tests 6.5 volts. Cranking, at same post ign, 2 it reads just 9.5, should be 12.5 correct? . THIS is a new switch. Is this reading of 6.5 v. at ign. 2 terminal in RUN position ( ign.1) correct or is that a tip off that I have a short in the pug that pugs into the switch??
If I check v. at the firewall bulkhead UNDER the dash, it reads just 9.5 v. like at the switch at ign. 2 post (brown wire).
Is there a short in the connection plug there at the ign switch or is the wire "bad" (brown wire) from the switch leading up to the firewall and/or into firewall bulkhead? Can a bad wire cause the V at switch the read less than 12.5 v.?? How do I begin to check this???
Let me re phrase. Is the only time I should get current at ign. switch terminal ign 2 (at brown wire), , when I turn key to start position. I should not find current there in run position (ign.1) Right ...????
Then I went back and checked for voltage at under hood bulkhead at the brown wire location, ( ign 2 start), when the key is in ign 1 position (run) NO current. When I turn key to start ( ign. 2) I get the same 9.5 v. at bulkhead.
Sorry if confusing!!!