head light help ,funky prob??

[boggerless]

the truck is a 79 and the cab is a 86. the head lights work,BUT when i turn them on the guages all bury. i've been told a short or a bad ground. i checked and cleaned all the grounds. also it drags on the engine when i turn on the lights.i just traced the wires coming out of the harness and there is a dark blue wire that goes to the right front turn signal.that is not conected to the harness but does end there. what does that wire do? ground ,hot?i'll never find were it goes in the harness. thanks

 

[diesel4me]

A shot at it...

I looked in my crappy Haynes manual that has a barely legible wiring harness diagram...I do see a dark blue wire from one front "parking lamp",splices into the side marker lights, then goes to #15 spot on the "bulkhead connector"(I assume thats the other side of the fuse box,where it unbolts)...but I cant see where it goes from there,it doesnt go the the headlight switch as far as I can tell..I'm assuming its a HOT wire,that is probably pinched somewhere,seeing its dragging the altenator down when you turn on the lights..my diagram is for an 83 truck,but 90% of them have the same harness color codes in the 80's.......good luck!.. ..

 

[boggerless]

thanks, bro. i'll check that now.

 

[boggerless]

there was a hot wire coming out o the harness. i hooked it up and it didn't do anything.i think its a dead wire.even as a ground it didn't change anything.