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Well I am brand new to the forum and hoping for some insight. I am finishing the restoration of a 66 coupe. Have put 125 miles on it as a "shakedown" and all has been working fine until 2 days ago; now have turn signal issues.
Here's the situation:
1. Parking lights work, front and rear
2. headlights work
3. brake lights work (lights on or off)
4. left turn signal works (lights on or off)
5. Right turn signal does not work (flasher unit clicks very rapidly, no dash indicator light)
6. emergency flasher clicks rapidly but lights do not flash (flasher is oscillating too quickly) and will blow fuse
So basically my left right turn signal does not work and seems to have a short. Rather than coming on and not flashing (indicating a bad flasher), the flasher clicks very rapidly but the dash indicator does not come on and neither the right front nor right rear light comes on or blinks.
Trouble shooting so far:
1. Disconnected both pigtails of both rear lights from the wiring harness (factory harness)
2. Unplugged front parking / turn signals from harness
3. Did some ohm-meter measurements
So with the above, there are basically no connections to the park lights or turn signals lights. Everything is unplugged at the lights. Yet, when I turn on the right turn signal, the flasher still clicks very rapidly, indicating a likely short in the harness. When I turn on the left, the dash indicator comes on but does not flash, as you would expect.
I then measured from each signal wire to ground (the "high beam" for each turn signal bulb at all 4 corners, as measured at the connector that goes to each bulb) and found the the right front and right rear "high beam" wires show a short to ground (looking back into the harness... the light sockets and pigtails show no shorts).
Now, I can understand that a short as described would cause the flasher units to click rapidly... what I do not understand is why the brake lights work fine...
Anybody have any experience with this problem?
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I was suspecting the turn signal switch... but the thing that makes no sense to me is that the brake lights work fine, even though that "high beam" on the left side measures as shorted to ground... so I do not see how the brake lights can work... but they do...
And yes, I have checked all the grounds... nice and solid, and all other lights / gauges are working fine... so I guess process of elimination says it is most likely the turn signal switch... and from what I read, they are problematic anyway.
You are confusing the fact the brake lights work with the overall problem - ignore that fact for a moment. To isolate if it's a switch or wiring:
If you disconnect the bulbs and still have a reading to ground there is a short (as you’ve surmised). I did not see that you also removed the bulb from the Right dash turn signal in the inst. panel since it is in parallel with the right front wiring, with that bulb in will also create a grounded condition.same with the left
To simplify the circuit instead of going from the lights in go from the source out:
pull the turn signal connector apart from the switch and remove all of the bulbs. Using the ohm meter, One by one isolate the wiring to each corner of the car from the TS car side connector. With the bulbs out there should be no grounds on any of the wires.
Wires of interest are:
Left front – Green white
Left Rear – Green Orange
Right Front - White Blue
Right Rear – Orange Blue
If all of the wires check out it’s a problem with the switch.
I did not mention the inst. panel indicator lights, as mine are LED's, not filament bulbs... (I am not using the factory cluster... it is a full aftermarket cluster and the TS indictors are LEDs) so they should provide no path to ground.
The problem acts the same whether or not any other bulbs, or any bulbs for that matter, are installed... as mentioned, not only are the bulbs all removed, I have also unplugged every light, at each corner of the car.
So I do need to isolate the switch and measure as you have suggested...
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