Blinker issue

[Tony71c10]

Noticed that my front driver side blinker with all of a sudden start blinking on its own without the key. It will blink for a few minutes then stop. It's weird. I did replace the turn signal a while back with an aftermarket one. Not sure if this is right but I can active the blinker to both side without the key. Any help is always appreciated

[dmjlambert]

Left and right turn signals operate only with the key on. The hazard blinker works with key on or off. Can you tell more about what you have going on? When you say "I can active the blinker to both side without the key." do you mean both sides at one time using the hazard switch? Does the hazard switch blink both sides in front and in back (all 4 corners of truck blinking)? What year is your truck?

Here is a wiring diagram
http://67-72chevytrucks.com/vboard/s...49#post7809749

Here is a helpful thread about the turn signal switch and testing
http://67-72chevytrucks.com/vboard/s...d.php?t=712235

[truckster]

Originally Posted by Tony71c10

Noticed that my front driver side blinker with all of a sudden start blinking on its own without the key. It will blink for a few minutes then stop. It's weird. I did replace the turn signal a while back with an aftermarket one. Not sure if this is right but I can active the blinker to both side without the key. Any help is always appreciated

Are you saying that the turn signal just starts blinking with the key off and you not touching anything, or that the signal works with the key off when you activate the turn signal arm?

[Tony71c10]

Originally Posted by truckster

Are you saying that the turn signal just starts blinking with the key off and you not touching anything, or that the signal works with the key off when you activate the turn signal arm?

Yes with the key off and not touching it.Without the key in the ignition my front drivers side bumper blinker with start flashing for a while then stop. Also without the key in the ignition , if I turn the signal lever to the left , both the drivers side front bumper blinker and the driver side taillight will blink. If I turn the lever to the opposite side (right) the same and only the driver's side front bumper blinker will start flashing. Not sure how it's getting power. By the way it's a 71 c10 .

[truckster]

One more question: when you say you replaced the turn signal with aftermarket, are you talking about parts inside the steering column or did you install a turn signal unit on the outside of the column?

Actually, I thought of another question: when it's blinking, do you hear the flasher unit cycling on and off?

[Tony71c10]

Originally Posted by truckster

One more question: when you say you replaced the turn signal with aftermarket, are you talking about parts inside the steering column or did you install a turn signal unit on the outside of the column?

Actually, I thought of another question: when it's blinking, do you hear the flasher unit cycling on and off?

I purchased the complete unit from CPP. The one with the red knob. Its a non tilt column. I pull the steering wheel and all to install it. I also hear the flashing unit when its blinking on its own.

[dmjlambert]

This is a weird problem. I suggest inspect your wiring carefully, especially where it connects to the turn signal switch and the turn signal switch wires that go up into the steering column. Make sure you don't have shorts or skinned wires.

The turn signal flasher doesn't have power with the key off, and the hazard flasher does have power with the key off. Both this switched power and always-on power go into the turn signal switch in the column, so any mix up is likely to be in the wiring to the column or inside the turn signal switch itself.

It could be a defective turn signal switch.

It is also possible there is a short from an area of skinned wires or by some random tiny strand of wire poking out where the wire is crimped to a terminal. By your description of the symptom it is logical that the light blue wire is shorted to brown wire. What do you get if you remove the hazard flasher module (the one near the "traffic haz" fuse)? Does the intermittent problem go away but the turn signal still work with key on and when you intentionally turn on left or right blinker? I'm thinking that hazard module must be the module you hear ticking when you have this unexplained sometimes front left bumper blink.

My additional notes from the wiring diagram I gave you the link to earlier:

[dmjlambert]

I also suggest use a multimeter or test light to test the fuse panel, to make sure each area or zone of the fuse panel gets power with key on, and areas that are not supposed to get power with key off are actually powered off. I find it weird that your turn signal works with key off.

Here is a diagram of the fuse panel areas.

http://67-72chevytrucks.com/vboard/s...98#post8004798

I am wondering if the turn signal switch has mixed up wires, such as the wires from the turn signal switch are not pinned into the right places in the plastic connector. It is possible you have more than one problem going on.