Tail lamp fuse wiring diagram needed for a 86 regal limited

[Geeness7]

I need the wiring diagram for the fuse box, an the wires that go to the light switch. for a 86 Buick Regal....
my 20a fuse for my tail lights blew one day ,after replacing the fuse, it blew again a few days later. I've been tracking the possible short down,but now need a diagram to finish.

 

[pontiacgp]

you can narrow it down by unplugging the harness on the left of the fuse box. That harness is for the rear lights and is made with solid aluminum wires which can corrode and cause a short. If the fuse doesn't blow it's either the harness or a socket or a bulb....

 

[Geeness7]

Thanks i will try that today. what color would that wire harness be or should I say what color wires are those all aluminum tail light wires? ...also after reading other post, i think you said to someone else to check the illumination wire behind the radio.. because ppl make a mistake an ground it sometimes....well i checked that an it's not grounded out right there, but somewhere along the line it is. cuz the contacts on both sides of the illumination light socket test as ground....would those aluminum wires being shorted also cause that?

 

[pontiacgp]

the brown wire is for the tale lights, you'll find a connector in the diver's side near the rear of the trunk that connects the aluminum wires to the wires that go to the light. Perhaps you can disconnect that connection to isolate the rear lights when testing a fuse.

 

[Geeness7]

Okay. ...well i disconnected the wire harness from the left side of the fuse box. an the 20a tail light fuse slot still showed that half of it grounds out when i turn on the parking/ tail lights. ...so i tested the brown wire in the harness an it still showed ground even after it was disconnected from the fuse box......so i disconnected the that wire harness in the rear of the trunk from the tail light wires....tested it again on that brown wire under the dash( while still disconnected from the fuse box) an it was no longer grounded....that should tell me that the aluminum wires in that harness is good .. right?.....also they appear to be in good shape on both ends that i can see....
also....after tracing the brown wire to the front of the car, i see where 1 brown wire connects to 4brown

 

[Geeness7]

connects to 4 brown wires....i disconnected the one wire from the 4 to isolate a possible bad wire... tested the one wire that goes back to the fuse box an it had ground still... while the 4 wires up front had different results. ...2 of those wires showed a strong ground ( test light was bright ) 1 wire had a dim grounded test light. an the other had no light wasn't grounded.... should the bulbs be in or out while testing the sockets an what's the correct way to test the system? incase I'm doing it wrong by using a 12v test light.

 

[GP_Vortec350]

the brown wire is for the tale lights, you'll find a connector in the diver's side near the rear of the trunk that connects the aluminum wires to the wires that go to the light. Perhaps you can disconnect that connection to isolate the rear lights when testing a fuse.

What's the name of the harness I need to buy a new one I took a pic of it

 

[pontiacgp]

If that is the harness for the rear lights I wouldn't look for one, I would make one with copper wire instead of that aluminum wire