i have a 70 chevelle blinkers dont work when you use the blinker but when you hit the brakes the front park lights come on why

Sounds like you may have a couple of problems...

When other light B comes on with light A it usually means a bad ground at light A. The one is using the other as a ground path.

The blinker non-op may be flasher or fuse or...

Had the same problem, pulled out the hazard button everything worked. Give it a shot, who knows!!

joe

Check all your bulbs, on my 70 1/2 Z28 someone had the wrong bulbs in the tail lights. Spent days tracing wires ect. Finally went to an old timer and in about 5 mins found the problem.

Make sure both flashers are there, and clean all the grounds on your bulb sockets. This would involve cleaning around the hole for the socket so there is good contact between the socket and lamp housing.