Have a 68 rs coupe. Can't seem to figure out the problem with the turn signals. The lft. turn signal would not blink so I cleaned the sockets on that side now the blink. But when I turn on the lights or parking lights the left side slows way down an almost stops blinking?? Could this be a ground problem? Also a minor problem is at the dash the rt. dorection green arrow does not blink but the lights do? Hope I have been clear enough with the problem. Hate piring problems so any suggestions would be helpful.
There is a ground wire on back of cluster,under the tach/fuel gauge.Alot of times these are missing,or disconnected.Sounds like your turn bulb is burnt out.Pull the cluster and check ground,and all bulbs.