Front indicators alternating when headlights on

[I AM CORNHOLIO]

Hi Everyone,

I have an issue with headlights, indicators and marker lights.

When the headlights/parklights are off, the indicator and side marker flash in unison.

When the headlight or parklight circuit is powered, the indicator and side marker flash alternately. Both sides do the same, so it does indicate the correct direction.

Is this a normal function? The truck (my prfile pic) is a 73C10 with (I'm guessing) an 83 onwards front and interior

Cheers

 

[75gmck25]

On my ‘75 GMC they always alternate.

 

[Dleslie212]

Hi Everyone,

I have an issue with headlights, indicators and marker lights.

When the headlights/parklights are off, the indicator and side marker flash in unison.

When the headlight or parklight circuit is powered, the indicator and side marker flash alternately. Both sides do the same, so it does indicate the correct direction.

Is this a normal function? The truck (my prfile pic) is a 73C10 with (I'm guessing) an 83 onwards front and interior

Cheers

Mine does the same, after a complete wiring harness replacement. It's just the way it works

 

[I AM CORNHOLIO]

Mine does the same, after a complete wiring harness replacement. It's just the way it works

I figured it might be. Thanks man!

 

[Goldie Driver]

One of the cool features I still to this day enjoy watching.

They are functioning correctly.

 

[Bloodhound1981]

Hi Everyone,

I have an issue with headlights, indicators and marker lights.

When the headlights/parklights are off, the indicator and side marker flash in unison.

When the headlight or parklight circuit is powered, the indicator and side marker flash alternately. Both sides do the same, so it does indicate the correct direction.

Is this a normal function? The truck (my prfile pic) is a 73C10 with (I'm guessing) an 83 onwards front and interior

Cheers

As stated, it is correct. It has to do with the fact that the side marker lights don't have their own ground, they are powered through the front turn signal bulbs. So when the parking lights are on, and the turn signal is activated, the side marker light goes out when the front turn signal activates, hence the alternating action.

 

[I AM CORNHOLIO]

As stated, it is correct. It has to do with the fact that the side marker lights don't have their own ground, they are powered through the front turn signal bulbs. So when the parking lights are on, and the turn signal is activated, the side marker light goes out when the front turn signal activates, hence the alternating action.

I wonder if I give those side markers their own ground? Have you or anyone ever done it?

 

[Bloodhound1981]

I wonder if I give those side markers their own ground? Have you or anyone ever done it?

What would be the point? They are ungrounded by design so that they flash on and off.

 

[Oldbear42]

One of the cool features I still to this day enjoy watching.

They are functioning correctly.

I set up the front signal lights on my Goldwing (when I replaced the side reflector with an LED light) the same way because I liked it on my old 89 GMC.