I am struggling to understand why my rear Brake Light and Turn Signals do not function when I have my headlight switch on.

1: Replaced sockets, bulbs. I even soldered more mercury on the two areas of the bulb that connect to socket for better connection.
2: Cleaned Black Ground wire for tail lamp assembly connected to frame near antenna.
3: Pulled brake light switch and cleaned - working correctly when headlights are off. (I may just buy a new one and install)
4: Checked Fuse Box and replaced Brake/Directional 20 Amp Fuse anyway.
5: Inspected rectangle connector (10 wires - for rear assembly) that is connected at fuse box.
6: Replaced Headlight switch - two months ago
7: Replaced Hazard relay - at fuse box and Directional relay at glove box - two months ago. Who knows maybe parts are defected.


Completely dumb founded why when my headlight switch is on - rear lights stay luminated by no brake light and directional (blinker) function. All works fine when headlight switch is off. I read thru all the forum posts that have had this problem - no success. Fortunately, I do not drive car a night often - maybe just have to live with. Totally crazy and defines logic to me. Any suggestion appreciated. By the way all other lights, Markers/Courtesy lights etc - work fine.

May just have to take to electrical auto mechanic and pay up - I am out of options.

 

With headlights off, brake lights and signals can ground through the tail light or running light function. With headlights/tail lights on. You now have 12 volts in that tail light wire and such grounding is impossible.
you have a bad ground at the rear of your car.

 

I believe that too - that makes sense. I am going to try and ground the bulbs directly next.

Thank you

 

Some good news, I grounded the passenger bulb, and working as should. Funny thing is removed the ground wire to the bulb and now also working as is should just sitting in the new socket - crazy. Moved to the driver's side, not as lucky, tried grounding the bulb no luck. I am confident the cheap new AutoZone sockets are the issue. Going to pick up another new socket for the driver's side today. I was suggested by a corvette shop, trying to install the Dorman 85822 bulb sockets, that were used on other GM years. The socket offers a better connection to bulbs. He claims you can all get that socket to fit into the tail Lense if need be.

My god these cheap Tawain aftermarket sockets that everyone sells are JUNK! Reading those corvette posts everywhere - keep you posted and thanks.

 

Success I finally got both sides to work! Let me share the success I had after speaking to my Corvette mechanic - stay away from the plastic insert tail sockets that most corvette vendors sell. My experience - they do not connect the bulbs terminals like the original GM sockets did. After trying 3 different sockets with bad results - here is the one that worked for me perfectly Dorman 85822 - medal ring surroundings. They also snap into the Lense retainers like a glove - pics attached and what would I do without Corvette Forum.

 

I bought a 1978 corvette in 2018 off craigslist for $9000. Have had alot of problems but it is running fine, very fast and i have my inspection sticket untill 9/1/2025. When i turn on my parking lights all my gauges go to the left. I had to replace all the wiring for my flashers) I had to replace my instrument panet (no light $1000) , i had to replace my temp and oil gauges. My head lights dont go up when the temp is under 50 (i had to use a screwdriver to get them to go up but they do go down. I had to get a screw for my drivers side door handle. I had to get a door spring for my drivers side door. My window broke 3 times, had to get a motor and regulator. Had to replace my windwhield almost didnt do it, HUGE rust hole, leaking water when it rains.