Brake lights out of sync

[tburns]

71 Charger, had it two weeks and am going through a checklist of things that need work.  My left side rear lights work fine when I go for a left hand turn signal (lights blink in unison), but the right side lights are blinking in an alternating pattern when I put the turn signal to the right.  Any idea why this is happening?  One thing to note is that the far right rear light was replaced at some time and has a new housing unit in it.  All the other ones are original.

[Plumcrazy]

Sounds like a bad ground.   One of the right light bulbs is using the other for a ground.

[Charger_Fan]

Sounds like a bad ground.   One of the right light bulbs is using the other for a ground.

As a result, one of the bulbs on that side will be dimmer than the rest too.