Turn signals not flashing

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Screamin demon72

Screamin demon72

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I have 72 demon with an American auto wire harness on the car. I also have digi-tails in the tail lights. With key on and engine off the turn signals flash normally and the emergency flashers work perfect. But With the headlights on, I can hear the flasher relay click slower and the front turn signals don’t flash at all, they just remain solid. The element in the bulb that flashes doesn’t remain solid, just the parking light element. I have tried changing my tail lights back to standard 1157 bulbs doing away with the digi-tails, made sure all grounding points were clean and also ran a ground straight from battery to the turn signal ground and none of that fixed it.

Has anyone else ran into this problem? I would assume the switch in the steering column works correctly being that it flashes perfectly with the headlights off. Thanks
 
I bet if you do the same test in the dark with the headlights off you will notice a slight lighting of the headlights with each turn signal flash. sounds like you are back feeding through the headlight circuit to get a ground.

I would verify that your turn signals front and rear have a good ground at each bulb holder. 4 double ended alligator clip wires about 24" long can be used to make a good temporary ground to each bulb holder.
 
Dana67Dart said:
I bet if you do the same test in the dark with the headlights off you will notice a slight lighting of the headlights with each turn signal flash. sounds like you are back feeding through the headlight circuit to get a ground.

I would verify that your turn signals front and rear have a good ground at each bulb holder. 4 double ended alligator clip wires about 24" long can be used to make a good temporary ground to each bulb holder.
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I will try those things later today. On my American auto wire harness the ground feeds the headlight and the turn signal. I cleaned the ground really good but I will check them again just incase
 
Headlight wiring is for sure something that should be upgraded. This strategy of older cars that were manufactured with the grounding they used was stupid then and worse now. Mopar is not alone. Improve the wiring size, add headlight relays, and separate headlight grounds, and use star washers and bolts and nuts instead of sheet metal screws Even the old headlight connectors (if they have not been upgraded are suspect.

"Digi" do you mean LEDs? Those are a problem all on their own, "generally speaking."
 
67Dart273 said:
Headlight wiring is for sure something that should be upgraded. This strategy of older cars that were manufactured with the grounding they used was stupid then and worse now. Mopar is not alone. Improve the wiring size, add headlight relays, and separate headlight grounds, and use star washers and bolts and nuts instead of sheet metal screws Even the old headlight connectors (if they have not been upgraded are suspect.

"Digi" do you mean LEDs? Those are a problem all on their own, "generally speaking."
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Yes that’s why I upgraded. Needed to be done. And “digi-tails” are a brand of LED tail lights you can get. They are an LED panel instead of just LED bulbs
 
But when you replaced the LED
with old style bulbs you had the same issue.

The thing is the turning on of the headlights caused a change in the turn signal AND the E flasher so it must be something that have in common.

Perhaps as simple as a wire connector in the steering column turn signal switch in the wrong socket of the plastic connector housing.

I have had odd things happen with bad / missing grounds.

If you are missing a ground in a tail light for instance, the power will go in one filament then to their common grounding point, not finding a ground there, through the other filament and then back down that filaments wire to another bulbs filament that does have a good ground.

If all 3 filaments are the same wattage they will all light but be 1/3 as bright.

If one filament is 10 watts and the other filaments are 40 watts the 10 will light almost as normal and the other 2 may not look to light at all.

Electrons will find a path if one exists.
 
I was trying different things this evening and I figured out that the front turn signals actually are flashing with the head lights/parking lights on, you just can’t hardly see it because the parking lights are on. Are the parking lights supposed to stay on with the turn signal flashing?

If I look super close at the bulb with the marker lights on, the turn signal filament is flashing but it’s not flashing brighter than the parking light filament so you can’t tell it’s flashing.
 
Dana hit it right on the head, vise-grip one end of a length of wire to the neg battery post, touch the other bare end to the actual metal bulb base, lites should work as normal.
With a poor/no ground at the bulb, the power comes to one filament of the bulb, but with no ground, - power goes up thru the other filament, (both filaments lit) back up that wire to ground at the indicator bulb on your dash.
Repair the grounds, test using that ground wire, in the trunk, vise-grip to the trunk lock striker in the middle.
Good luck.
 
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Inertia said:
Dana hit it right on the head, vise-grip one end of a length of wire to the neg battery post, touch the other bare end to the actual metal bulb base, lites should work as normal.
With a poor/no ground at the bulb, the power comes to one filament of the bulb, but with no ground, power goes thru the other filament, (both filaments lit) back up that wire to ground at the indicator bulb on your dash.
Repair the grounds, test using that ground wire, in the trunk, vise-grip to the trunk lock striker in the middle.
Good luck.
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Here’s is the wiring diagram from American auto wire. Iv checked it 2 or 3 times (Iv had this wiring harness on the car for 4 or 5 years now) and it is wired this way exactly. If I do the ground wire test and it works, should I run 1 separate ground to the headlight and 1 separate ground to the parking/turn signal bulb? It’s currently sharing the same ground
 
Supplying a known good ground is the first step in a process of elimination.
Being an aftermarket wiring harness, there's a lotta variables, including who installed it.
By your description of both elements on dim is a very common no ground symptom. Your dash indicator lites should be on dim as well.
 
supply a separate ground for your individual turn signals at each bulb fixture - you know your car had them before you "upgraded" to Autowire...
 
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Just went thru this on my Demon, make sure you have a good ground. Anyway that was my problem, thanks to the help from the guys on here.
 
I was finally able to figure it out. I did have the feeds reversed. The turn signal was flashing the dimmer parking light element in the bulb and the turn signal element was on with my running lights. I swapped the 2 feeds that come into the plug for the parking/turn signal and now it all works correctly. I had it wired exactly like American auto wire says but they have it backwards for the 3 connector plug
 
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