I have an optima battery in the car that is solid. claimes it does not need an alternater to operate.

My headlights flicker after about 20 mins of night driving. Somewhat randomly

It's just the headlights,

not the side markers
not the front running lights
not the back lights

these lights work fine,

But the headlights flicker,

ANY ideas?? thanks in advnace!

 

Could be light switch, or, unplug and plug back together.
Other lights don't show flickering because they don't emit the light power headlights do.
Measure battery power during operation to see if alt is steady or not.
This event will tell if regulator needs replacement, or light switch.

 

loose connections?

 

I'm betting on the H/L switch...

 

Thanks everyone for the help. Also, nice to hear from you again as always Everett!
I will test these suggestions and post my results.
​​​​​​​Thanks again very much appreciated!!

 

Thank you, Sir. Nice to be heard from - Stage 3 Cancer survivor. Good luck.