Could someone please help me ?

[tarheel]

Greetings, I have a 1989 240sx Se .One of the problems I am having is with my headlights, the blame things will pop up on turning on the headlight switch on the steering column. But on turning the lights off by the same switch they do not go down . The same with the dash mounted switch . I have replaced the relays( which were taken out of a wrecked 240 ),checked fuses and that has made no difference . Is there any way that I might check those relays to see if they are indeed bad or good? Question (2) The wires going to the air condition compressor have been broke off ,cut off or burned off , what color are the wires that are to connected there and what harness do they come out of and where it would be located at ?Question (3)The wire going to the oxygen sensor has burned into , on looking at the wires there are (2) . One that wraps around the interior wire that has insulation around it. Is the outer wire just a heat shield wire ? If not what is it for ? Can I just splice another wire on to it and wrap it with some heat reflecting tape ?

Thank you for you time . allen .