Ok, I know I must be missing something simple here so maybe you all can help.

1966 Oldsmobile Vista Cruiser. Turn signals stopped working. They turn on, but do NOT flash. Replaced the whole cancel cam and harness in the steering wheel. Still don't work.
The 4-ways work perfectly though.

And in this 1966 model, the 4-ways are turned on with the the big pull **** under the dash (not sure if this was a dealer installed add-on or installed later). Both the turn signals and the 4-ways run through the same flasher so the flasher is working fine.

What would cause the flasher to work for the 4-ways and NOT the individual turn signals. I don't know where to look or what else to test. All bulbs seem to be working fine and, again, flashes perfectly for the 4-ways.

Thanks in advance.

 

The turn signals and 4-ways use 2 different flashers. The add on under dash pull **** unit has it own flasher that plugs into it:

There is a separate flasher mounted under the dash that is for the turn signals. If it is not on the fuse block it is held in a spring clip mounted near the column up under the dash.

 

All the Flarestats I've seen have their own flasher attached to the back of the underdash unit.

Look to the left of the steering column, behind the dash, and I think you'll find the turn signal flasher.

 

Flarestat was a factory or dealer installed Olds/GM option in 1966 and there were even dimples in the lower dash to show where to drill the switch mounting holes. There were earlier generic versions too but if it's like the one LoadedW34 has pictured, with the harness, it's the correct 1966 unit.

 

So, time for troubleshooting 101. First, if the lights come on but do not flash, the switch, harness, cancel cam, etc, are NOT the problem, as you painfully found out. The only failure mode that prevents all turn signal lights from flashing is a bad flasher module. A look at the wiring diagram will show you that the flarestat hazard flashers use a different flasher module, independent from the one for the turn signals. Replace the turn signal flasher module.

 

Thanks for all your feedback so far.

I'm not sure there is a second flasher in my 4-way switch as it's currently kicking on the external flasher mounted next to it under the dash. I can hear and feel it. I even attached a new flasher module not mounted under the dash to verify this. Additionally, the 4 ways DO NOT flash when that single external module is removed. I think my 4-way **** simply connects a circuit with the 4 turn signal wires and uses the one external flasher. I'm going to pull it to verify.

My new theory is that (somehow) the turn signal wiring is getting power from somewhere else and not from the flasher circuit. Going to test all wires today.

Definitely an annoying issue.

 

There is.

 

If you have the Flarestat unit pictured, unplug it from the car's turn signal wiring at the bottom of the steering column and then connect the TURN SIGNAL SWITCH wiring directly to the car's wiring harness. That takes the Flarestat out of the circuit and eliminates it as the problem.

If you have a generic one that was spliced into the car wiring, I have no wiring charts for that.

 

Actually, they are trivially easy. The Flarestat unit is just a four way switch. The aftermarket ones typically have four blue wires (in addition to power and ground). Each blue wire gets spliced into one of the four wires to the turn/stop lamps at the four corners of the car. It doesn't matter which goes to which. With the Flarestat off, the system functions normally. With the Flarestat on, the separate Flarestat flasher powers these four lamps, which are now all connected together through the Flarestat switch. Note that if you step on the brake pedal while the Flarestat is on, now all four lamps are connected to the brake light circuit and all four will light up. The factory hazard flashers on 67-up cars work exactly the same way, but that circuitry is all built into the turn signal switch.

 

Here's the 66 shop book A-body Flarestat installation diagram. Amazingly to me it shows only one flasher, as do the FSC and Toronado diagrams.

And the instrument panel wiring diagrams on none of them show turn signal flasher location for a car without Flarestat.🤔

 

The turn signal flasher is up on the backside of the dash, as shown in this drawing from the 1966 PIM. The flasher in Glenn's illustration is the SEPARATE one used by the optional Flarestat.

 

Thanks again everyone for all your help.

So yes, I have the flasher mounted under the dash next to the 4-way pull ****. I've tried 3 different flash relays in there. Obviously none work. I tested and get power at the brown wire at the flasher plug.

And I already disconnected the 4-way switch and ran the turn signal wiring directly to the car's harness. Same situation where they don't flash. I did this early on because I thought something broke inside the 4-way unit that was causing the issue.

I will get to the bottom of this later today.

 

Which is NOT the flasher that controls the turn signals. See my drawing above.

 

You are a hero!

That was it!

It was buried under the dash deeeeep in the insulation. Never noticed it.

I knew it must be something small I missing.

Thank you and thanks everyone for chiming in to help.

 

It's always the small things that bring so much joy...