1968 sequential turn signal help

I’ve researched and read the diagnostics, but can’t seem to pinpoint the issue.

I am using the West Coast Cougar’s solid state sequencer. I am getting flashing power to all the orange lines. Purple is solid 12v. Green is dead. This is with the turn signal up in to the right hand signal position. I have 12.7v on all wires that are hot. The left turn signal doesn’t seem to work.

My brake lights and parking lights work.

Appreciate the help

(quote) I’ve researched and read the diagnostics, but can’t seem to pinpoint the issue.

I am using the West Coast Cougar’s solid state sequencer. I am getting flashing power to all the orange lines. Purple is solid 12v. Green is dead. This is with the turn signal up in to the right hand signal position. I have 12.7v on all wires that are hot. The left turn signal doesn’t seem to work.

My brake lights and parking lights work.

Appreciate the help (quote)

The green highlighted circuit is for the RH turn signal. So you are saying that both turn signals are inoperative? What about the emergency flashers?

Hazzard gives me same result as the right turn signal. I get pulse to the same wires. But no bulbs flash. I don’t seem to get anything in the left turn signal circuity. I did a very quick run through this morning. I am going to go through it again at lunch.

For a light bulb to work it needs power and ground. Which one is missing? Sounds like you have more than one issue.

The bulbs are grounded, since the work when parking or brakes are on. I am leaning towards the power piece. I am getting power up to certain point in the circuit. But it doesn’t seem like the sequencer is sending the power out. The piece I need to learn/understand is what inputs to the sequencer will not allow the output. I have the old original sequencer that’s may or may not work. It’s on the rough side, but the motor does spin. I could try that, but doubt I have different results.

Thanks for the help Royce, seems like you’ve answered some of my other threads. It’s appreciated for sure.

What I have learned is that the turn signal switch is the highest failure item in the system. The other thing I have learned is that the AMK nut kit for the tail lamps often insulates the body from ground. When that happens you have neither turn signals nor emergency flashers. An ohm meter will tell you if the tail lamp housings are grounded. Also the ground wire from the wiring harness needs to be connected. It bolts to the structure next to the fuel filler.

I need a switch regardless, so I may go ahead and order that.

Could the ground be such on the lights to allow brake lights but not signal? I do have the ground wire to the neck filler hooked up.

Use a meter and measure. The brake lights could be getting a ground from the parking lamp circuit through the front lamps.

What’s the best process to measure the resistance of the housing?

Connect one lead to the ground wire bolted to the car. Connect the other lead to the end of the stud on the housing. It should be zero ohms or very close to it.

Did you replace just the sequential motor (SQM) or did you replace the entire junk in the trunk (K8/K9 , K10)?

First, your highlighted wires are for the K10 Emergency Relay. The K10’s purpose in life switches power for the inner and outer taillights for the Turn signals, disconnects power to the inner and outer taillights when HZWSW ON. The purple wire should have power when the ignition is on and the hazard switch is OFF, the only time when there is no power on this line is when the hazard switch is ON.

Your two orange highlighted circuits are the output of the K10 and should have flashing power when the purple wire is powered ( assuming you have properly grounded the K10 ). Note for completeness, you have highlighted the output of the K10, the 2 un-highlighted circuits are the inputs from the . . . Sequential Motor (SQM).

So with that out of the way, why doesn’t your green line have flashing power? Well the output of the K10 relay flows to the K8/K9 directional relay which it in turn (no pun intended) selects the Right (K8) or the left (K9) bank of taillights. Check circuit 440 the white wire feeding the K9 relay for power when the turn signal is in the right hand mode. If there is no power here with the ignition on and in right hand mode then your turn signal switch or wiring to this circuit is suspect. Likewise check circuit 441 the violet wire with the turn signal in left mode.

Good Luck and let me know if you need any additional information

Coach Jack

Found the issue and its all workinf now. Unfortunately, i wasnt the one who took the harness out. After studying tje schematic 40 times i realized the passenger side harness comes across under back window and ties into the driver side.

Thanks for all the help folks.

Speaking of that harness that goes from passenger to driver side. Can anyone send a pic or explain how it should be routed across the car? I fed it through the channel closest to the trunk lid. It’s about 6 inches wide and where the hinge springs sorta tuck in.

Thanks

It attaches to the underside of the package shelf using clips that are available from WCCC.

Wire routing

Thanks folks those pics are very helpful.