240sx question!!!! what is this wire connected to could it be the defrost or the antenna for the radio?! oh and its connected to the hatch and its on the drivers side.

Its unlikely the defrost wiring goes all the way to the top. I think you will find the top 5 inches will be the radio antenna wiring.

Lol, there are actually 2 grids on the back window, one is for the defrost, the other is for the radio antenna. Your mechanic probably has the wires on the wrong tabs on the passenger side. He has the radio antenna on the defrost grid and the defrost wire on the antenna. Take it back to him ans explain your issue.

the antenna is on the rear glass behind the right side molding at the rear glass is the connections for the rear defrost and ant check the wire connections

Between the rear passenger window and the back window is a junction where rear defrost wiring and radio antenna connect. Rear defrost wiring becomes loose and burns this unit out. when looking for replacement at salvage yard everyone of them I found had burned up. Lots of La Sabres w/o working rear defrost. I made solid connections for defroster, and added an antennae, not much point in repeating a system that will fail again.

The antenna is part of the back glass. The antenna wires to pick the reception up are the same ones that defrost your rear window in the glass. You can check the connections behind the back "C" pillar posts. If the grids are broken this will reduce your reception.

check that the antenna cable is still plugged into the back of the radio and plugged into the bottom of the antenna at the finder to check radio end insert 4 large paper clips into the square holes in the front corners of the stereo this disengages the lock mechanisms slide the radio out and check the connections if electrical antenna check the fuse on the back of the radio that it isn't blown if so replace. loosen the inner fender panel and see if cable still connected to antenna #2 check the fuse for the rear defroster its probably blown if so replace and check for any grounded out hot wires also check the connections at each end of the rear window sometimes they become corroded or unglued from the window, if any of the fine lines that cross the window have been scratched or removed partially this will also render the defroster inoperable

ok so either sides the same so remove all panels behind the lights to expose all the wires. Then make sure you have a 10mm nut driver, locate long threaded skinny bolts with small short nurts on them. I believe there maybe six or more in that one section to remove the light. You may have to pull hard because there might be a sticky seal holding it in place. I dont think its from the light i would replace the weather stripping around the entire hatch before removing lights

Remove the shift knob. Starting on the console around the shifter, gently pull up on the "bezel". When it comes off you'll see the radio's held in (with the little storage area) by 4 Phillips screws.
The wiring is hidden behind

Just remove these trim pieces (start with the ash tray) I have also included the wiring list




Wiring

Constant 12V+: Red/Black
Switched 12V+: Blue
Ground: Chassis
Illumination: Red/Blue
Dimmer: Red/Yellow
Antenna Trigger: Black/Red
Antenna Left Rear

Front Speakers 4" x 6" Doors
Left Front (+): Blue/White
Left Front (-): Blue/Yellow
Right Front (+): Brown
Right Front (-): Brown/White

Rear Speakers 6 1/2" Rear Deck
Left Rear (+): Red
Left Rear (-): Green
Right Rear (+): Blue
Right Rear (-): Pink


Please rate this a fixya

If the radio is aftermarket, they cross the circuitry of the antenna near the defroster, causing static in the antenna everytime you turn it on. Disassemble the radio and check for the wiring. Worst case scenario: they used the Positive wiring for the defogger switch and connected a wire to the radio's ACC cable.