Front Turn signal HELP

[6S1568]

My front turn signals stop working when I pull on my headlight switch. All bulbs, sockets, connectors, fuses, and grounds checked and functioning properly. Flashers work as they should. 
BUT, once the headlight switch is activated the front turn signals STOP blinking. The rear turn signals and marker lights work as they should, it's just the front two turn signal bulbs that stop blinking and stay just lit.
Upon further testing at the front turn signal sockets, with the bulbs removed, I'm getting 12 volts on both the turn signal side of the bulb tip and the parking lamp bulb tip when the parking lights are turned on. With the parking lights off and the turn signals activated, only the turn signal side of the socket carries 12 Volts, like it should.
Any ideas where this head light voltage could be leaking over to the turn signal side of the circuit? Could it be in the turn signal switch in the steering column itself? Thanks in advance, Denny     

[69 GT350 Vert]

It could be a bad headlight switch as well.  What happens when you turn on the console toggle switch for the rear running lights?  Bad flasher due to extra load?

[TOBKOB]

What happens when you turn on the console toggle switch for the rear running lights?

?   

[Bob Gaines]

It could be a bad headlight switch as well.  What happens when you turn on the console toggle switch for the rear running lights?  Bad flasher due to extra load?

I think you need to clarify what you mean by "rear running lights."

[trotrof1]

When you checked the grounding points did you physically disassemble & clean them? Just a visual inspection can be misleading. Also wiggle the wiring to see if the strands are weak or broken beneath the insulation. 50+ year old wiring can get brittle. If that pans out then check the connections at the T/S switch and H/L switches and connections between those and the T/S lamps. Still sounds like a bad connection or ground to me, possible corrosion issue.

[69 GT350 Vert]

I should have said Interior toggle switch on the console.  I'm pretty sure that turns on the front and rear side marker lights, the rear tail lights, and the dash lights on my car.  I don't believe the front turn signal running lights turn on with the Interior toggle switch on my car, but this is going from memory. 

[Bob Gaines]

I should have said Interior toggle switch on the console.  I'm pretty sure that turns on the front and rear side marker lights, the rear tail lights, and the dash lights on my car.  I don't believe the front turn signal running lights turn on with the Interior toggle switch on my car, but this is going from memory.

One toggle switch is for the fog lights and the other for interior lights only and not rear and side marker lights. Rear and side marker lights are controlled by your headlight switch .

[6S1568]

To answer a couple of your questions:

I did replace the headlight switch, and no change in results.
I did physically pull the ground wires and clean the ground wire terminals, screws, and frame points.

Could it be one of the flasher units? I think there are two, one for the turn signals and another for the four ways, is that correct? Thanks

[Dan353]

Cougar's Unlimited LLC has a troubleshooting guide for 69-70 Shelby's on their website try that.  It was helpful when I had a problem with my 69.  They might even have the part you need.  Or try calling them

http://www.thuntek.net/cougars_unlimited/69seqts.htm

[TOBKOB]

If your console toggle switch operates anything other than  (a) fog lamps or (b) interior lights, then this is your problem...sounds like someone has butchered your wiring somewhere...Good luck...

TOB

[6S1568]

Thank you, Dan. I'll use the Cougar troubleshooting guide next and see what happens. 

TOB, fog lights and interior lights are all testing good. Thanks

[TOBKOB]

I should have said Interior toggle switch on the console.  I'm pretty sure that turns on the front and rear side marker lights, the rear tail lights, and the dash lights on my car.  I don't believe the front turn signal running lights turn on with the Interior toggle switch on my car, but this is going from memory. 

My bad...I responded to the wrong post...

TOB   

[Coralsnake]

You havent changed bulbs lately have you?

[6S1568]

I put all new bulbs in two days ago, as part of my trouble shooting. Bench tested them all prior to installation. Thanks

[Lincoln tech]

Park and turn signal wiring switched ? front turn signal working ok with headlights off ? which filament lights ?