LED Brake Light / Directional Issue

[mass-concealed]

So I’ll get right to the point here. 

 

1997 GMC K2500 5.7 

 

Installed all new tail light lenses and new headlight lenses. All new LED bulbs in everything. 

 

Was getting hyperflash, replaced flasher with new LED one, problem solved. 

 

Last issue I'm unable to figure out is my directionals work fine if my headlights or parking lights are NOT on. As soon as those go on break lights stop working. Also the side marker direction stops working as well during this. Only ones that remain working are the ones under the headlights. Only brake light I haven’t changed is the top center one and that one works all the time. 

 

Seriously not sure what is going on any help is appreciated!

[Sebastian Lundström]

Check if you have good ground, i have heard of similar problems when there's been a bad ground

[mass-concealed]

I am this weekend my brake lights below the tailgate are all junk and corroded so I’m going to clean that up and replaced them.