I have the wiring diagram for the car, but I'm having trouble tracing the wires from the trunk forward. The rear lights work, but the blinker/brake lights on the rear passenger side only do not. Bulbs are all fine. The cancel cam in the steering column is broken - left signal works fine, but right must be held up to get the front blinker and dash indicator to blink - because these work I never thought the rear lights weren't flashing or the passenger brake lights weren't coming on. If this could be the issue, I'll start taking off the steering wheel to repair what I can. Any idea which wire(s) I should be tracing from the dash panel back? I see the white/black and orange/black coming from the brake light switch, but I can't determine which wires send power to the green wire that causes the brake and blinker to work on the passenger side. If anyone has had this issue, any help is welcome.

 

Use a test light or a volt meter on the brake light socket when depressing the brake pedal. See if you get voltage to the socket.

 

There is no power to the blinker/brake side of the socket when the brake is pushed or when the blinker is activated.

 

Can you physically trace the rear passenger brake light wire in the trunk towards the back seat and test it. Start to isolate where it may be possibly open?

 

In these videos, he tests the circuits in the '67 Toronado steering column. Maybe you could follow along with his checks to help you narrow down which wire is giving you the issue. This is for the tilt/tele column though.....is that what you have as well? If so, those switches are very difficult to find.

https://www.youtube.com/watch?v=B_M6rQhsUM8&t=305s

https://www.youtube.com/watch?v=rK8AgNyrt0s

 

Good or bad, yes, I have the tilt/tele with the cornering lights. Completely impossible to find the wiring harness. Even though the video gets a little blurry on the details for a short period, it does appear that a dark green wire is the lead for the right side blinker/brake bulbs all the way back to the steering column. I'll see if I can follow it back from the trunk. At some point it won't have power and that will be the repair point. Honestly I should start at the column to see if power is getting to the pin initially. Seems like it should, but I had a large wiring repair with that connector about 6 months ago. Could be the issue. Never thought there was a problem since the front bulb blinks! Thanks for the vids

 

The power should be getting to the pin initially because the turn signal works in the other direction. The switch just takes that single power supply from the flasher and directs it to either the R or L side depending on switch position.

 

In the '67 CSM, have a look at Chapter 12......in the turn signal diagnosis section. In the '66 manual it is on page 12-46 & 47.

I found the diagrams here much easier to use than the wiring diagram to help figure out how the system worked when I was troubleshooting my rear lights. It doesn't help that the '66 wiring diagram isn't correct as well. Anyway, have a look.

 

That's perfect. In the '67 CSM these are on page 12-53. So it confirms that there is one wire that carries the power from the turn signal switch through two connectors and to the lights in the back. At some point I either have a break in the wire or the turn signal switch itself is broken (and I know there is something broken in the column). I'm going to start at the column and see if there is power coming through the switch itself to the rear lights - dark green wire. If there is, then there's a break somewhere between there and the trunk. Thank you!

 

Ok, so checking for power in the trunk area shows the light green wire (driver side) has power when braking and when the blinker is applied, but the dark green passenger side does not. This leads me to think the issue is with the large curved multi-wire plug at the column. Does this wire get a signal from the brake light as well? I'm thinking it must, but again, I can't quite make out the schematic that shows this. My secondary thought on this is that the cam inside the column is broken, and I'm never actually sending a signal to the blinker to blink - but that doesn't explain the brake light not working, does it? I'm going to check for power and good connection at the column plug, then I suppose it's time to remove the steering wheel and see what's up under there. I'm sure a broken piece made from unobtanium, as usual...

 

Do you happen to have a picture of the schematic in your '67 manual that shows the operation, like I showed from the '66 manual?

In my case, and I'd bet it's the same for yours despite being a different design, when the signal light isn't 100% cancelled the brake light will never work on that side. My signal light would be cancelled enough to turn the blinker off but not enough to be back to the center......this would take out the brake light.

 

I read electrical diagrams like I read Russian... Thank you for the translation, lol. My diagrams are the same as yours, and now that you explained how one affects the other, I understand why the brake lights don't work. The repair I need to make is in the column.

 

When you actually have the RH signal light flashing, does the pilot light flash as well?

 

If you do have to go into the steering column, CFair has a great writeup on how to disassemble the parts. I know the wheel itself is a little different than on the '66 so there will be some differences in this part but the real difficult part is taking out the C-clip for the horn ring and I believe that part is the same. I have linked the threads below where Chris (CFair) shows how to do it with the best chances of not damaging it:

https://classicoldsmobile.com/forums...9/#post1523439

https://classicoldsmobile.com/forums...-wheel-138493/

I hope this helps!

 

The front signal light and the pilot light flash when I hold the indicator arm in position, but the back lights never blink.

 

After reading through those threads, maybe I just need to adjust the Bowden cable? I'll crawl under later and see if I can see what I'm looking for and if I understand how to adjust it.

 

I don't think you have a bowden cable. That was only on the '66 as they had the turn signal switch mounted down towards the bottom of the column and the cable connected the switch to the stalk. The '67 had it all internal in the center of the steering wheel like most cars that came along later on.

 

I believe the '67 tilt and tele switch looks like this one. It's not mine, just from my collection of pictures I've stashed during my research. On the '66, this switch isn't internal to the column and is mounted down below. Both are rare and very difficult & expensive to track down.

 

Those are fantastic pictures. I compared these to the '67 manual and you are correct. These match up with the exploded drawing of the '67 tilt-tele column. Maybe this could be a more straightforward repair, if that's even possible. At least I should be able to see the issue once the wheel and surround cover are removed.

 

Reviving this thread, as it is still hanging there with no resolution - and the brake light/blinker issue still technically exists. In the past year I have gone through the column, cleaning all the contacts and confirming all the wires in the column and under the dash are in good shape. The biggest problem with this issue is that the power circuit is wildly inclusive, and so many things are powered by this one always-on feed to the bottom left of the fuse panel. I have cleaned the connections as I could, and used a product called Deoxit liquid to apply on connections for oxidation removal and improvement of contact, and it has helped. There are several threads revolving around my dash removal and installation that have dealt with various other issues I have run into.
HOWEVER - this particular light issue is intermittent and to date has been somewhat elusive - everyone I described it to stared at me in wonder/horror that a single side of the taillights wasn't getting power for the brake/blinker filaments. After finally getting the car on the road after almost two years, I have noted that randomly the interior lights will be off when I open the door. This is the "signal" that the brake lights and taillights will not work. I addressed this by cleaning the DOME fuse contacts and making sure the fuse was in good condition, as sometimes the solution to getting the lights back on was to wiggle the fuse. But that didn't always work. A couple times the solution was to jiggle the light switch, or to turn the lights on and off several times in a row. The first few pulls would do nothing, but when the headlights popped up, I also knew the brake lights would be on. I found one more solution yesterday, and maybe maybe maybe this is the real deal. The driver's door jamb switch came into the picture when I decided to push it in and out rather than closing the door over and over while testing the circuit. Wiggling/push-pull of that switch seemed to make the ground connection needed, and the brake lights popped back on right away. I'm hoping that some electric cleaner has cleaned it up to the point where the connection stays solid, as I'm a bit wary to change out the switch completely. But I think that the original issue with the light circuit may be the door switch ground. Strange how these connections can affect so many different things, but that seems to be the way of these cars. I'm not familiar with the simple door switch replacement - when do they ever go bad? - but I would welcome any input on the best replacement part and installation tips. Do I need to pull the wire from the back side, or can I unscrew and remove everything from the front? Thanks everyone for all the help as I have slogged through this mess!!!

As a quick edit - after getting all the lights working last evening, I went back to the garage this morning, and they wouldn't work again. It took a number of presses/wiggles of the lock switch and several on/off cycles of the headlights to get them working again, over about a 3-4 minute period. What gets me is that they will all work fine, but the next morning be off again. Maybe the common denominator is that the door jamb switch is depressed and won't ground well the next time the door is opened (?). I'm not sure how the headlight switch seems to work its way into this conversation... and by the way, it is a new switch, not that it couldn't be defective in some way. Ugh.

 

I have to give this some more thought, however, what I do know is that your rear brake/blinker lights shouldn't be finding their ground connections through the door switch.

I had a similar intermittent fault showing up on my '66 and the way I got to the bottom of it was using two Ipads on a Facetime call. I had one, outside, pointed at the taillights so I could watch them while sitting in the drivers seat playing with things until I could reliably fault them.

 

The only thing I can think is that the door switch ground is causing a fault somehow in the entire circuit, not that the ground for the lights should be found in that spot. The other common denominator with this issue is the on/off of the headlight switch, which *sometimes* will not activate the vacuum to raise and lower the lights; but when it does, the brake/blinker lights work. Faulty headlight switch? Occasionally with all the on/off/on/off the whole shaft will pull free from the switch completely. If I can get this problem to happen again, I'll take a video "from failure to fix" of the process I go through to make it work. As of now, they are all working again. I wish I could figure out what causes it to fail.

 

So lets clarify a little, what do you got?

Tail light running lights when you pull the headlight switch? Both sides working reliably?
Brake lights? The RH brake lights are intermittent, correct? The LH works reliably?
Signal lights? The RH signal lights are intermittent, correct? The LH works reliably?

With regards to the headlight switch:
The headlights only pop up occasionally when the switch is pulled? The headlights work regardless even if they are down? The reason I ask that is because the headlight switch doesn't control anything in the brake/signal light circuit, only the tail running lights.

To me, the simplest circuit in this system is the brake lights. I think I would start with those and see if you can get them working and hope you stumble upon the issue along the way.

 

 

Ok, thanks for the clarification.

I mentioned earlier that the brake lights have no connection to the headlight switch and I think that's a pretty good clue that something is really wrong. It would definitely be helpful if you used a test light to see where the power is missing along the circuit. However, in order for the brake lights to be influenced by the headlight switch, the only thing I see that jumps out at me would be at the tail lights. That's the only area where those two circuits come together (other than the flat body connector harness). Barring any funny stuff going on, those two spots would be where I'd be going. Like I said, the brake light circuit is super simple and there's not much along the way that would screw it up. The turn signal switch in the column being the most obvious and notoriously troublesome.

 

Well, the car has been on the road enough lately that the justling and jarring of travel seem to have shaken everything into their final resting places. The taillight/brake light is now officially out on a permanent basis. None of the earlier tricks have made any difference in the situation as it now stands, however a jiggle of the blinker stalk this morning got the lights to momentarily come on. Now things are pointing directly at the blinker switch in the column, which I know is not completely perfect, but which I had apart and cleaned thoroughly some time ago, making the lights function again when they didn't at all previously. The contacts under the turn signal switch assembly were filthy and not making a connection at that time, and I left the broken right turn cancel cam bit in place, which means I have to hold the stalk up to make a continuous right turn signal. At this point I think I would be best off to leave it alone until I can pull the entire column and replace/repair the wiring harness, or find a professional to do that. If there is anyone currently doing this kind of work, I'm all ears (and checkbook). As a reminder, this is a tilt/tele column and the car has cornering lights, making a blinker switch swap a near impossibility. Repairs are the only remedy.

 

Yeah, sounds like your column switch is definitely the issue. That will 100% take out your brake lights/signal lights in the same manner as mine did but the switch itself is a different design. I thought you mentioned that you replaced that switch already?

With regards to repair options, you could always contact everyone's favorite Toronado man in New Mexico, John Dorcey. He's the best and if I was you he'd be my first choice if he could provide you with a replacement switch. You could also contact that Eldorado George guy in Florida (just search him on Youtube). He rebuilds those particular steering columns and turn signal switches and could probably fix you up as well. I must say thought that I don't get particularly good vibes from him but he appears to do outstanding work. He's costly for sure.

I keep hoping for 3D printed replacement parts to start showing up. Maybe someday someone will take the initiative. It's really annoying how cheap little parts like these can take your car out of action.

 

Yeah, I took the switch apart while it was in the column, but it was a clean up job only. Completely taking the broken piece out (the one that holds the stalk in the right/left turn position) required removing the entire harness through the column, and probably needed more technical ability to replace than I have. There are replacement pieces/parts that can be swapped in to these switches, but assembling them is the issue. Those rivets that hold the moving pieces together are pretty specific. Honestly, the parts I cleaned and reassembled were making good contact, and I'm surprised that the connection isn't currently (pun intended) being made to make the lights work. I'm going to check what I can on the wires themselves just in case there might be some continuity issue somewhere, but wow, it's difficult to trace what wire is going where.

 

It occured to me that the '67 and up Eldorado used a very similar tilt-tele steering column. I bet you could get a switch from a Caddy and it could be made to work. It's possible, I suppose, that the wires may be a different length but that's no big deal.

 

I know you're right about this, and it's worth trying to locate an old column, as I would guess most Caddy's had cornering lights - the harnesses should be the same.