'68 Turn Signal Indicators

Sorry guys, yet another thread on turn signals!

I have read as much stuff as I could find and I think I know what the answer is but thought it best to check with the brains trust here before shelling out $100+ on a potential solution only to find it doesn’t fix the issue.

What I have is an electronic sequential turn signal controller in the trunk (sorry, don’t know make/model) and the sequential turn signals work just fine. Front turn signals work OK as well. The issue is the indicator lights in the dash come on when the turn signal is engaged with a single click from the relay, then the lights just stay on and dim slightly as the turn signals operate rather than clicking on and off as they are supposed to do. I am using standard bulbs all around at the moment.

So is my problem 100% sure to be the K5 relay in the dash? I take it there is no point replacing it with another identical unit if I plan to upgrade to LED bulbs in the future? Is my only option to buy the equivalent electronic in-dash relay (which I believe is C8WY-13A366-AR for the '68)?

Thanks in advance.

The indicators are a common problem in 67-68’s, even with all stock bulbs and electronics. The new solid state K5 relay (68 version) will solve that problem, whether you have standard bulbs or LED’s.

For those with a '67, it’s slightly different and was designated K7. Here’s the solid state version for 67.

These were specially designed by Vic Yarberry for the Cougar. The trick was integrating a small speaker into the new relays to mimic the mechanical click sound that the old relays made.

I recently did a little before / after video to show it in action:



Hope that helps!

Quick question. Does the new relay mimic the way they would have worked fresh off the lot in 1968, or is it a “better than original” replacement?

For Blitz, I had a K5 installed and I still have the problem with the dashboard lights not working. I do have it in the same shop in part to take a look since now one of the taillights is out so it’s possible it’s an installation problem.

Good question, I’d say it’s probably a little better, in the sense that it consistently works without hesitation. So I guess you could say it works like the originals would have fresh off the lot, but more reliably. The click sound is a little different.

Only thing I can think of is that it’s not grounded well. It needs to be securely mounted to the factory metal bracket where the old one was.
Also I don’t know if you’ve replaced your sequential unit in the trunk but that could be something else to look at.

Thanks Blitz - I was hoping to avoid that. The most confusing part of all this is that something changes for the worse anytime someone lays hands on it.