Brake Lights Tail lights Turn signals

i have a 1978 Mercury Zephyr im having issues with my brake lights and front driver side turnsignals.... all of my brake lights and turn signals work untill i turn on my head lights and then my driver side turn indicators quit working and mt brake lights quit working but my tail lights work fine.... i replaced every bulb in the car.... ive checked the wires and replaced bulbs and i did notice some cracking in the plastic of the light sockets.... what would cause these lights to quit working and where can i find replacement light sockets... thank you for your help

Sounds like you have ground issues. Motormite (Help) should be able to supply you with the correct sockets. Advance, Autozone, NAPA should all be able to get you what you need. I'm gonna hazard a guess, and say that the ground pin (which is on the side of the socket) may be gone. Does your left turn signal indicator come on and stay on when you turn on the lights? Also, check all of your ground wires, and the terminals where the wires ground to the chassis.

I hope this helps.

Later,
Mike.

When i turn the lights on my left hazard indicator stays lit.... With the lights off my indicators work properly.... Thank you for you input i will check the ground wires again and the grounds on the sockets

Well i dug into it again today.... i replaced 3 sockets and i found a place in the harness where someone cut the wires and taped them together i cut the wires and reparied that mess..... The problem was they had the tail light wires on the brake light side of the socket and brake light on the tail light side .... there was two hot wires running to the same circuit so the turn signals was overloading.... final results i have turn signals head lights brake lights and tail lights...... everything works wonderfulll final cost 28$ for 3 sockets

Glad to hear you got it licked. It's always good to figure out the electrical crap!