Where do I begin? 1970 T/A
 

1970 T/A: Problem; the tail lights and the brake light always stay on. The tail light harness, the headlight switch and the turn signal switch are all new and recently replaced. The ground wire to the trunk latch area is clean and tight. (all of the headlights and parking lights in front work correctly) Where do I start to see why the lights are always being powered up? There is no trunk compartment light in this car. Thx.

The fact that the brake lights are constantly on makes me believe it's the brake light switch. I'd check there first.

Agree.
Unplug the wire connector at the brake switch and see what it does.

The front lights work normally, like off when light switch is off?
How about when brake is pushed, front come on?

When light switch is off, the rear lights are still on?
Check the body connector going to the back half also.

:confused:

Are the rear side marker lamps staying on too?

update.
 

I unplugged the brake light switch and tested the connector. The orange side is always hot and the white side is cold. Once disconnected, there is now no power to any of the tail lights. When I plugged the switch back up to the connector, I used my test light to the switch and noticed that both sides of the switch are always hot with the plunger (on the switch) both released or pushed al the way in. I believe this proves that the switch is not shutting off power ever. I will replace the switch . Sound about right?

Sounds good to me.
(meaning switch is bad)


:)

Sounds like the switch is toast.

Good news bad news
 

Good news:I replaced the brake light switch and now the tail lights only illuminate when you activate the H.L. switch. Bad news: the brake lights do not activate at all. All 4 bulbs are the two element 1157s. Is that the correct bulb? Also, when the brake light switch plunger is relaxed/extended, only one side of the switch is hot. Shouldn't both sides be hot. Thx.

Yes, 1157 (or 2057) is the correct bulb. Have you double checked that they're Ok?

Yes, with the switch plunger fully extended, both with connectors should be hot. Bought a defective switch?

Your 4 way flasher could be shorted. This can cause this symptom.

I replaced the new switch with a new one from Napa and they are working properly. What are the odds of getting a bad switch!! Thanks.

Probably greater than we all think. It seems as quality on many parts have deteriorated.