*UPDATE* - its not the headlights blowing the fuse. The parking lights pop the fuse as soon as they are turned on....
*Having this crazy issue with my car where the parking lights go out every time I turn my headlights on. My brake lights work fine.When the headlights are switched on, it blows fuse #4 In the under hood fuse box. I replaced the fuse but every time, the parking lights come on and then immediately Off again with another blown fuse. Brake lights work fine in the turn signals work fine it’s just the parking lights. I have recently Replaced 6 x 9’s and Front components/head unit. I also replaced passenger side power window motor. Everything was fine after each upgrade....the problem came last week . I removed my trunk to repaint it the wiring that goes from the car into the trunk runs along the trunk arm thing along with the manual release cable for the trunk. My manual release cable has been damaged for quite some time. it pulled off of the clips & Would tighten now & again due to my trunk opening and closing. I’m assuming that the wiring might’ve been pulled at also.. Can someone please tell me the best course of action to take? I’d like to test the parking light and headlight circuits to check for continuity, but I’m not really sure how to. Any help is appreciated... thanks again

 

Does the fuse blow when you just turn on the parking lights and not the headlights?

 

no, everything was fine with just parking lights, As soon as I turn the headlights on the lights on the back came on for about a second and then went right back off... And the fuse was blown again

 

Yo, i was wrong. The fuse does indeed blow as soon as i turn on parking lights. They come on & go right back off

 

I'd say you have a short on the "hot" wire.
Best way to find it is to disconnect all the connections to the tail lights, head lights, etc... ( anything to do with lights).

The plug them in ONE at a time.Turn on the head lights, after each time. If the fuse does not blow, then plug in 1 more and keep going until the fuse blows, then the short is in the wire that you just plugged in.
However, if everything is disconnected and it blows the fuse, then you must have worked on something and pulled a wire that removed the insulation. If you worked on something recently, then look again at the wires in that area.

Do you have a multi-meter?

 

I'd look closely at the wiring in the trunk to see if there is any obvious damage to the plastic harness cover or open wiring. Also look at the wiring/connections at the headlights.

 

check all you light housings for water especially the rear because of of age they tend to leak and allow water to fill up and blow bulbs