headlight switch shorted out! but no blown fuses???

[mikeith]

ok the other night i was driving around in my 73 and someone pointed out that my running/taillights werent working, but headlights, brakelights, and turn signals were.... i figure not big deal i'll mess with it later.

well i pull out and realise my brights were on and pull the switch for the lever for the high/lows and i hear a pop. then realise i have no headlights....

i get parked and check fuses... they're good so i reach under the console and squeeze each of the terminals and then the gauge and running lights come on but still no headlights.

i take the back roads home and once i get home i take the column cover off and then ALL lights go out except blinkers and brake lights (which is normal)

upon looking over everything i notice that the thick gauged white wire w/ the red line on the headlight switch had apperently melted the soldering and popped loose(i came to this conclucsion by touching it back to where it was supposed to be soldered and it immediately got really hot then stopped all of a sudden as if it shorted out)

my first question is if that thick gauged white/red wire is supposed to be spliced into the main dash harness directly(because it was) and there is a thick gauged red one that is done the same way.

also the 9 pin plug that does actually plug the headlight switch to the main wiring harness melted the corner when it shorted out (the green wire w/ white line)

does this sound like it is the switch itself that is bad or the dash harness itself? how SPECIFICALLY do i tell if it is the dash harness... once i unplugged the switch everything was ok but if i plug it in the green/white wire gets hot.

i dont want to plug in a new headlight switch if its going to immediately short out

EDIT: pictures added
Modified by mikeith at 6:14 PM 6/8/2009

[evildky]

the wiring on these cars is notioriously bad, the ground wires are crimped together and run inside the loom and grounded at only a couple of points much further apart than they shoudl be

the cause of your problem I'm sorry I guess you'll just have to do a lot of testing, but the headlights are switched hot, as in direct power to the switch then straight to the headlights, this would be a good time to wire in a couple of relays and take some of the strain off of the swithc and get more voltage to your headlights which will give you a lot mroe light

[mikeith]

how do i do that? i thought about doing a painless wiring kit but i know NOTHING about wiring and that is a HUGE project. i read a couple links on hybridz and got REALLY confused.

how do i even start testing to see where i may be causing the short? and im guessing its from a power wire touching a ground somwhere right?

should i just follow the thick white wire and see if it grounds out anywhere or would it be the thick red wire i need to chase down? is the green/white wire that i showed is melted a hot or a ground wire?

sorry for all the questions... for someone who is decently mechanically inclined i dont know much on wiring

oh and how would i wire in a relay

[evildky]

MSA sells a relay conversion kit, it's pretty simple, basically you send the switch signal to a realay instead of direct tto the headlight, the relay then conects the headlight to a fused source run direct too the battery, less voltage and amperage loss

as for trackign the issue, has there been any recent chnages int he wiring at all?

you can measure conitinuity from the burtnt contact to ground, it should have zero continuity, if there si some continuity there is a short, and you get to hunt it down, first step would be disconnect the head lights and parking lights and side markers and retest, if that clears drops the continuity to zero you have a bad socket of fixture, replace the bad part, if it's between, all I knwo to do is unloom the harness and find the problem