my 87 has a loose wire under the dash. not sure which one yet but if i reach under the dash with the key on everything lights up. what color is the ground wires under the dash. before i picked this car up the previous owners son got mad at her and grabbed the wires and yanked on them and splashed paint on the car. i hope top get this car running by winter because my pickup is worthless in the snow.

Ground wire is generally black with white stripe.

Is there anything not working or the wire causing other issues?

All the best sorting it out

Cheers

Bennie

It would help us all if we knew what model '87', carb or spfi, EA81 or EA82 engine to understand what wiring harness it has. 

Would help if we knew what is wrong if anything. We all have loose wires, especially former owners son who sounds like he needs fixing first!

it is an 87 dl wagon with spfi i think it is an ea82. sorry it has been a while got married wife had a stroke, i had a heart attack you know life. but i got the bearings in the front hub and the new seals and the new brake lines, going to get the new rotors soon as well as the drive lines used and reboot them.

Geez mate rough trot!!

 I hope all is on the mend!

Cheers 

Bennie

Trace out where the wire comes from.  At least witch branch it is in.  There are not any separate wires. 

FWIW, it is unlikely that a single ground wire is causing this problem.  ALL of the dash wiring has multiple, redundant, web of ground wires that ground to several points throughout the body. Nearly all of them are simply black.  There are one or 2 systems with individual B/W wires at the item for ground, but they ALL tie back to the all black spider web of grounding in the harness.

I would suspect the wiring that goes to and from the interior dimmer switch.