1968 Dart no brake light on left side

Completing 1968 Dart long time project. Trouble shooting electrical issues. Read carefully, I have no brake light on left side of car when pedal depressed. All lights and turn signals work properly. Checked all wires for continuity before putting back into car. I checked and tried all the following:
1) Tested continuity on all wires leading to left taillight. This includes everything from turn signal switch to taillight including grounds. Tested ok
2) Checked continuity inside turn signal switch. Tested ok
3) Tried running ground wire to taillight socket. Didn't work.
4) Switched bulb from right side. Bulb good, still no brake light.
I'm lost on what to check. Any ideas. All wires check good. Only two wires at socket. Green wire ending at turn switch, and black ground.

Look into the socket.Ill bet the brass contact is deep ito the plastic piece that holds it.Saw that a lot.Ive been able to pull the brass out and get it higher in the holder.Thats as long as if you said you have poer to it.Did you use a test light to make sure you have 12 volts at socket?Rocky

I did check prongs already, they are ok. No voltage when brake depressed using yest light. Right side has power when depressed.

Believe it or not I had a similar issue many years ago. The brass contacts were worn in the socket & I was broke. I put a drop of solder on the bulb contacts...and it worked for years.

The only times I ever ran into this situation it ended up being a bad turn signal switch.

If the turn signal on that side is working then the socket and connections are working. Replace your turn signal switch in the steering column. When testing the turn signal switch for brake lights you should have two wires with current, one for each tail light.

agreed, from the connector behind the drivers kick panel rearward you are good cuz they both use the same large filament in the 1157 bulbs. Seperate the TS harness & in the column half of the pull apart connector with the stalk in neutral there should be continuity between the white wire which is the power coming downstream from the brakelight switch into the TS harness/switch & out to both of the "out wires for the dr/pass brake lights. that'd be a start. EDIT www.mymopar.com will have the colors for you but both should be hot at the same time in neutral (both brake lights light up when the turn signals ain't in operation).

Check your fuse holders also. I had a similar problem. Brake lights would work, then wouldn't work. Or turn signal would/wouldn't. I tried everything. The only thing I hadn't replaced was the fuse box. I replaced that and everything works great. The fuses were not making enough contact. 50 yr old connections are not the greatest....

RapidRobert you are correct in your statement. That's why I posted this question. I checked the turn signal switch with an ohn meter for resistance between the white wire (feed wire) and the green (left taillight) and got continuity. Also checked the brown (right taillight) and also checked good. The same green wire also feeds the left turn signal which works fine. So what the heck is going on?

Has to be a ground issue with that left light, or the more common turn signal switch-wiring. Wouldn't hurt to make sure the hazard switch is not involved too. Anybody recall the 76 cutlass turn sig issues, where the two(upper and lower) regular taillights would drop out(one of the two) while turn sig or brakes were applied? Seem some newer Geo cars do it too. Step on brake at nighttime, and the whole side rear lighting would drop out. Not enough current got through ground circuit to feed all the extra filaments of tail and brake lights together.

How about with that TS harness connector halves seperated, you jump fire to the green wire in the downstream half of the connector & see if the green wire behind the drivers kick panel is hot which I'm sure it ain't now but that would for sure pin it down to somewhere inbetween those 2 points. I ain't up on how the hazards are wired/interact with this & someone had posted a pic of the TS harness & where each wire goes to but I dont know how to access it. Opens happen at the terminals/connectors/switches so just me I would take a peek at mymopar for the diagrams then grab my meter & I ALWAYS pull a batt cable BEFORE switching the meter to ohms (& you will do voltage checks also). Short version: I would start at the TS harness (green wire) & work downstream.

I agree with some of the others. May be the turn signal switch. My Charger at one time the left brake light would not work. Turned out the weight of the turn signal stalk would drop just enough to not allow the brake light to not work but not enough to actually flash the blinker.

Have you tried holding the brake pedal down and moving the turn signal switch slightly both ways with the key off. If the left brake light comes on then you have a switch problem. There are a number of contacts in the switch that can get corroded. The signal lights and the brake lights are different sets of contacts.

The tail light and brake light are two separate circuits. That's why there are two filaments in the 1157 bulb. If the green wire out of the turn signal switch feeds the left turn signal then it also feeds the left brake light. Retest the green wire from the TSS while pushing the brake, it should have current as the brake pedal is compressed, if not the TSS is bad.

Ran the test that stumpy recommended. Held the brake down and fiddled the TSS arm, the brake light did come on a couple times with a quick flash. Also checked the flashers while I was out there,no flashing on left rear light. So it looks like it all ties in with the TSS. Looks like I need to replace it. Something not right with it, even though it checks good with ohm meter. Will update you guys tomorrow after installing a new one.

Stump is the man! I learned something today. We're getting closer.

Sometimes the screws come loose, check the one holding the stalk & the switch too.

Snug them up & try again just to be sure.

We can all sleep well tonight. I took a switch out of another steering column I had laying around and installed it into the Dart. Everything is now working as planned including the left brake light. I tested the one I took out of the Dart and found no reason why it won't work properly. All wires have continuity and all connections tested properly. Thanks for all the input. It proves 9 heads are better than one old one. Now onto hopefully the last electrical issue, the instrument panel lights won't work. Picked up a new light switch today, will start on that one tomorrow.

I agree

lift the turn sig stalk slightly to see if it comes on.

I don't know how many times I got pulled over for the left rear tail/brake light out.

I would always lift the stalk to make it work.

chased it for yrs till an old mopar guy said "just" change your TS switch.

and "BOY" on that 68 if you adjust the reverse light switch on lower column they will go off when in drive.

Have you replaced the turn signal switch with anything other than NOS?
It's been a known problem for years that the "parts store" replacement switches or the ones off the HELP! Brand rack were never cast properly and are warped making poor contact.

I chased this issue for months on my old Dart until somebody recommended I just get a junkyard part and be done with it. That's what I did and the turn signals worked again.

Scratchin I forgot about lifting the turn arm a bit.Now I remember when my 69 Bee had brake out on left side Id do that.Rocky