Hello all,
I have some questions for you about the 1967 original turn signal and 4Way flasher.
1967 F100

For some background: The truck has been mine for almost 4 years now, however it has been in the family longer than I have. I daily drove it for 1.5 years with minor issues, nothing I couldn't work out. That being said, I do not remember a time where the turn signal was as fast as a "normal" turn signal. I was always very slow compared to modern cars.

Fast forward to this Easter weekend, I had ordered a replacement part (flasher) that I thought was correct and decided to pull the cluster and replace it. I wanted to replace it because it was so slow that sometimes other drivers would not realize I had it on or were slow to realize. So I pulled the cluster and found the "mystery flasher" as other posts and forums have called it. The part # (Ford engineering# / Ford-ID# ?) is : C7TB-13350-A (I pulled it apart and found that some of the wire in the coil was burned but it was functional)
I can't find one online and it has been long obsolete, I read on fordification that this part was a 3-month run and after that, the part was switched to 2 independent flashers (fordification link below)
I also read that people replaced it with the heavy duty cylinder shape relay of the later models and it worked fine. Me being cheap saw a claim that any old relay would do the trick so, I went and got a 2 prong relay from the parts store and hooked it up (just made a spade connector to let the factory wire connect to 2 male vs the original male-female). Now, the lights are constant. I push the indicator left and my left lights come on but never flash, same goes for the right and emergency or 4Way. I think this might have to do with grounding but I am not the best when it comes to troubleshooting circuits. The reason I think grounding is that the original flasher has a wire from the relay to the casing making me think that the casing grounds the relay to the mounting location.

So my question would be, why would a regular, modern 2prong flasher relay make my lights stay on?
Here is what i came up with but i figured a new forum post would get more attention than trying to revive these.

Mystery Flasher? - Page 2 - The FORDification.com Forums
https://www.ford-trucks.com/forums/1...-location.html

I will try to check back here often and answer any questions you may have for me. I can also go get the PN for the new flasher but it's just a generic $4 flasher

Thanks, Ken

 

How about going with the original style Ford part? The following N.O.S. places show it in their stock. Ford part number C7TZ13350B.

Klimesh Motor Sales

563-562-3241

Green Sales

(800) 543-4959

Dennis Carpenter Ford

800-476-9653

 

I have a 67 with only 1 flasher. I have used standard flashers and they work fine. I switched to a “Super Loud” flasher (can’t remember brand, it was about $18) and that also worked fine. All the regular 2 prong flashers work fine in mine.

you used the words “relay” in your post. The flasher is not a relay. Just a thermal switch.

 

I bought what I thought was the right part before opening it up. I had to make a 4 hr drive and needed something to work. My only concern with getting the NOS part is that it would be just as slow as the "working" one I pulled out.
Can you speak on the speed at which the signals are meant to flash?

 

Cbrown is correct. They are thermal switches. The heat generated within the flasher to create the flash is created by the "load" of the front, rear, and dash bulbs. If you are using the correct 1157 and 194 bulbs as originally, it should flash as in back in 1967. Now if you've switched to newer aftermarket LED bulbs, as an example, the original style flasher won't work right. You would need a special flasher made for LED bulbs. LED bulbs are not close to the same load.

 

When the flasher is getting old and tired they get slow. I just replaced mine (1971 f100) for that reason. It was steady on for several seconds then would start slowly blinking. As it warmed up it would blink a bit faster but still quote slow. And would sometimes almost flicker flash. New flasher and now she blink a blink a blink a just like she should.