99 Silverado turn signal issues

[Austin Deuning]

My turn signals stop working when the headlights turn on and the indicators in the cluster illuminate solid. What could be the main issue? 
 

I’ve replaced bulbs and LCM. 
 

im not sure if it could be the harness, grounds or headlight relay 

[richard wysong]

Bad grounds possibly on the headlights

[Austin Deuning]

15 minutes ago, richard wysong said:

Bad grounds possibly on the headlights

Where would I find the grounds? 

[dna9656]

35 minutes ago, richard wysong said:

Bad grounds possibly on the headlights

Hey Rrichard! I side with you, if it's weird and electrical it's grounds!!!

[richard wysong]

On the radiator support. DON'T GUESS! get a test light or DVOM and test the grounds. Very possible that there is a bad body ground

Edited January 28, 2025 by richard wysong

[Austin Deuning]

4 hours ago, richard wysong said:

On the radiator support. DON'T GUESS! get a test light or DVOM and test the grounds. Very possible that there is a bad body ground

I know the harness, headlight relay and grounds are 25 years old