My recommendation would be to stop chasing your tail, and buy a complete LED set up from wccc and install it all.
The improvements are out standing better and you will know every thing is working !
Oops, I replaced the backup lights at the same time and got my numbers mixed up. The fronts are correct!
Also, a 552 flashes too fast and may not allow enough time for the 2nd and 3rd bulbs to turn on.
However, since only the inner most bulb on each side is turning on in brake light mode, it points to a bad sequential controller/connector.
Whatās the recommended flasher? The WCCC site referenced the 552 flasher so thatās what I went with.
Use a D0WY-13350-AR for both the turn signal and emergency flasher.
It has a longer (~1.2 second) cycle time instead of .3 to .4 second cycle time of a 552 flasher.
I have a ā68 and have installed the LED upgrade kit and the solid state sequential unit from WCCC. Everything works fine except the far right passenger side light when the right blinker is on. The bulb lights up when the light switch is pulled so Iām sure the bulb is fine. Is this most likely the connection at the socket or is the wiring the more likely culprit?
Try swapping the bulb with one of the other bulbs to determine if the bulb or socket is the problem.
Tinkered with it a bit more, suddenly the left center joined the party as well? But inconsistently. I started wiggling wires to see if anything was loose, and in the process wiggled the sequential box. Stuff started pouring out of the box, so I popped it open to findā¦
I donāt know, can anybody spot anything wrong? 
Time for an upgrade.
You can reuse the black plastic case - after cleaning.
Hopefully, the red and black connectors can be separated and are not corroded.
If they are, replacements are available.
I cranked and yanked and pried on those connectors quite a bit and couldnāt get them to budge. I have some Weather Pack connectors lying around from another project I may use instead.
Unfortunately, Weather Pack connectors wonāt match the original connectors as used on the original or upgraded sequential controller.
I had these pigtails made up to solve this problem:
Holy F! Itās a miracle any bulb anywhere did anything.
Thanks, Vic. I swapped bulbs with the inside socket and now both work perfectly.
Hi, I have a 70 cougar with the original blinker module and when I activate the right turn signal the Sequential blinker Works fine, but when I activate the left turn signal all of the blinker lights activate together not sequentially. When I turn on the hazard lights the left side blinks all together while the right side is sequencing.I was wondering what might be causing this.
The left left side is operating in brake light mode. This could be due to one or more problems:
- missing flashing left front signal on green/white wire at the controller in the trunk
- bad ground for left front turn signal
- wrong bulbs (drawing too much current) in left side marker lights - try unplugging them to see
- bad sequential controller (shorted output transistors or open diodes)
Thank you Vic for the help. I found out that the rear left marker light does not flash with the blinkers. It seems like somebody added a ground so it only stays on solid when the lights are turned on. Also should the right side be sequencing when the emergency flashers are turned on? I was also wondering if the relays on the blinker module should be clicking because they donāt seem to be doing anything? I disconnected all four and nothing seemed to change.
Vic will steer you straight but Iāll add that on my '70, replacing both mechanical flashers with his new digital units cured a myriad of ills. Well worth the money.
On the 1970-1971 Cougars (and other Fords), the side marker light ground is routed through the front turn running light filament.
Because of the low resistance of this filament, this routing causes the side markers to flash with the turn signals.
But when the headlights or running lights are turned on, the side marker lights flash the opposite of the turn signals
(OFF when turn signals are on, ON when turn signals are off. A modification such as you describe may affect the turn
signal operation unless it was done to the lights in all four corners and then the side lights will no longer flash during turn signal operation.
The side marker adapter kit, that I designed, rewires the side marker lights to use a ground wire for each bulb.
The circuitry retains the original flashing feature while allowing the use of LEDs in the front and side bulbs.
With the early original sequencers, the emergency flashers do not sequence the rear lights.
Sometime in 1971-72, this changed (on board marked 2L7-0135-01) where the rear lights do sequence during emergency operation.
The original āLittleFuseā brand relays, used after 1/1/70, commonly fail where the contact arm breaks off - rendering them useless.
These relays were used to eliminate the voltage drop inherent to the transistors used in the original sequencers.
These sequencers will still work when the relays are disconnected.
So I finally got time to try and diagnose the issue and I finally found it. The quarter panel had been previously replaced and the body shop that did it must have cut the wire thatās runs from the front marker light to the blinker module. Thank you Vic for all the information it really helped me diagnose this one.
68 XR7. Mechanical sequencer replaced with Cougars Unlimited unit. Turn signal relay is original. Hazard relay is original. Rear center lamp wonāt flash with turn signals or hazards. Thinking maybe my hazard switch is bad? Hereās whatās going on:
Engine running, headlights off:
Brakes:
All three brake lamps on each side illuminate when brake depressed.
Turn signals:
Turn signal indicators flash each way.
Front turn signals flash each way.
Rear turn signals skip center lamp and flash 1,3 in each direction.
Hazards:
Turn signal indicators both flash.
Front turn signals both flash.
Rear turn signals both skip center lamp and sequence 1,3 on both sides.
Engine running, headlights on works the same as above.
I have a 1968 base model cougar. I have the solid state sequencing box in the trunk, new solid state flasher under the dash & everything worked.
Out of the blue, the turn signals totally stopped but the brakes, hazards and rear lighting with the headlights all work just fine.
I replaced the turn signal switch but this resulted in no change whatsoever. That orange wire with the inline fuse has power.
All parts are from WCCC.
Is the inline fuse holder itself to blame?
I have a 69 cougar and Iāve been looking for this little 15 C.B. for the hazards and brake lights and I cannot find it for the life of me. I have the same issue, just recently installed plasma LED with the kit from WCCC along with the flasher unit replacement. Worked for a little while, but then, all of a sudden, No flashers and No brake lights. Signals work, running light work. Front flasher lights work. I have to believe that it is this 15 C.B. Does it have to be reset or replaced?
thanks friends!!!
Stace