Everything you wanted to know about '67 Sequential Signals

When you tell some one that you own an early Cougar, more often then not, they will say something like “Oh yeah, they had those cool tail lights!” It seems to be the one thing that people remember about cars that were built over 40 years ago. So keeping those cool taillights working is pretty close to the top of the list for most Cougar owners.

Fortunately for us, Coach Jack feels the same way. And he did more than just make his work he has assembled the best most comprehensive collection of Cougar tail light knowledge ever. Like 29 pages worth! Even if you are not driving a '67 I think this comprehensive look at how the system works will be very valuable to any one working on these systems.

And thankfully Coach Jack has agreed to share this with all of us. In appreciation of his effort, we have made Coach Jack and honorary Supporting Member and this thread will become a sticky. We look forward to seeing lots of perfectly flashing Cougar taillights!

I like this line the best: “Understanding how your cat’s lights flash in the blink of an eye”
You will want to down load and save the PDF.


You can read more about how Coach Jack produced the guide on the ClassicCougarCommunity.Com home page. https://classiccougarcommunity.com/

Again with the Calssic!?

“Function: adjective 1 : serving as a standard of SECONDARY excellence, not the best 2 : almost historically memorable, but may soon be forgotten 3 : not quite …”


Well that is highly coincidental! We just spent 5 hours with Cougar Greg (user name devildog) doing a video titled “Everything you wanted to know about 67-68 Sequential s” yesterday. We will make sure and point people to his very well laid out work. This is a HUGE benefit to WCCC, we get a mirage of electrical questions everyday and they are usually impossible to solve over the phone. Also do not forget this thread when trouble shooting your taillight issues.

Watch for the video mini-series to be released soon! (Just Kidding)

A short shout out to Don and the wonderful family he has assembled at WCCC for the opportunity to help!

Sorry for the hijack (Jack), please resume normal programming.

Looks like a great troubleshooting guide. Who exactly is Coach Jack? Maybe a little bio would be in order.

I can’t seem to find a link to a PDF. Is it intended to be inside the [url] tag in the original post which doesn’t have a url in it?

See post #2, Scott…

Yep, I made the rookie mistake of copying the text instead of the URL… DOH! Fixed it now though

Is there an equivalent body of info for 1970 tail lights? Or are they the same system?

Unfortunately the 69 and 70 taillight systems are vastly different than the 67. I helped another Cougar enthusiast with his 69 looking at the 69 wiring diagrams from WCCC web site.

Vic Yarnberry has a web page for troubleshoting the 69-73 sequential taillights http://www.thuntek.net/cougars_unlimited/69seqts.htm

Hope this helps.

Coach Jack

Thanks Jack.

I have a 68 Cougar, and while under the dash tried to locate the Flasher can / turn signal relay. Unable to find it, does someone have a pic taken from the floorboard of where the can is located? Any picture that would show where I should be looking would be great. I am assuming the reason my turn signals do not work, is because the Blinker relay is missing or wired wrong by previous owner.

This is the back side, the front facing you in the dash has some circuit breakers and what not. Mounted to the WW motor bracket.

HA HA … That sux… I purchased a “Flasher Can” that said it was for my Cougar ( I am used to seeing them on my VW BUS) and I was looking all over for a stupid barrel flasher. Back to the floorboard!

To help troubleshoot your issue I have a few questions:

  1. Does the emergency flashers work? - If they do work, then the K7 Turn signal relay is not your issue, indicating a high probability that your turn signal switch is bad.
  2. Have you verified that the 15 amp inline fuse is OK?
  3. If the emergency flashers are not working, have you verified that the circuit breaker is OK?
  4. Assuming power is now going to the turn signal switch, have you verified that circuit 458B has power when in left turn mode?
  5. Likewise, have you verified that circuit 458 has power when in right mode?

Note circuits 458 and 458B provide the input power to the K7 Turn signal relay.

If you really suspect your issue is the K7 relay, you can bypass the relay as a test by disconnecting the K7 harness and placing a jumper wire across circuits 458 and 459. Circuit 459 will provide the input power to the Sequential Motor.

Hope this helps.

Good Luck.

Coach Jack


In Devil Dog’s picture, I am pretty sure his is of a 67 and the two relays shown with the wires are the K5 and K6 relays which your 68 does not have. The relay hanging off to the left of the picture is the K7 relay.

Coach Jack


Thanks for the informative document in the 67 Cougar Sequential Lights which I have worked my way through to try get my 68 lights to work, but I am still seriously confused and not getting there with the sequential turning lights. All the light functions do what meant to (I think), so maybe you can steer me in the right direction in the turn lights. I have installed a solid state replacement, and removed the sequent motor. The blue wire from the solid state in connected to the K10 relay at 514 (blue). Configured as such, the turn light activate the inside tail lights only (no sequencing). The emergency switch activates both center tail lights. The combination of the two (right or left turn, plus emergency) activate both side in sequential mode. Looks great, but I’m sure its not correct. If I switch the blue lead from the solid state to K10 into the 436A connection (yellow), then the sequencing activates (on both sides) on the emergency switch only, and the turn lights only activate the inside tail lights.

Any ideas ?

with reference to the earlier posts, I have a single barrel flasher under the dash


The Solid State Sequencer does away with the sequential motor (as you pointed out) but it also does away with the sequential relays and the K10 relay.

You are correct that the blue wire from the solid state sequencer connects to connector P79 (which was plugged in to K10) on circuit #514. Circuit 514 should have power when the hazards are off, and are de-energized when the hazard swith is on.

Your last post mentions you have a flasher barrell? The Cougars do not use flasher barrels as the Sequencer motor expects constant voltage to the circuit. You should have a 3 wire Turn Signal relay C8WY-13A366-A for a 68 Cougar. (Note this is a differnt part number than a 67)

I would check the voltage on circuit #459 Orange-Green wire at the Solid State Sequencer in 3 different modes:

  1. Hzsw OFF, Turn signal in Right
  2. Hzsw OFF, Turn Signal in Left
  3. Hzsw ON, Turn signal in Center

I suspect that in your case, #3 above will show a higher voltage than #1 or #2. This would indicate a problem with the turn signal switch. If however all 3 tests have the same voltage, then the Solid State Sequencer is suspect.