I have a 1987 Ford F150 all my lights work but the park lights in the taillights. My break lights work but at night my park lights doesn't any thing would be helpful.

 

If I'm reading this right all the lights front and back work except the tail lights when you have only the park lights on , do they work when the headlights are on?

 

No

 

First things first - these bulbs are dual filament bulbs - one of the filaments illuminate to running / parking lights. the other is for brake / turn signal / flashers.

Might just be two bad bulbs! that is the first thing I would check....

 

I have brand new bulbs. I scrapped the prone to get a better connection still not working

 

Are they dual filament bulbs?

 

Yes

 

I would check the switch to see if you are getting any power going to them, if you do start at the lights and check for a loose or broken wire,ground problem and if someone has added a trailer plug be sure to check there first.

 

Ok thanks