Taillight fuse blowing out with headlights

[68MoparCharger]

hey, i've got a question for anyone who might know what's going on. My rearlight/taillight fuse is blowing, it stays together while braking, turn signaling, and the emergency flashers work too. Only when I turn the headlights on does the fuse blow.   I've replaced the taillight harness, dash harness, front light harness, and engine harness. I'm not sure what's going on. Any idea's can be helpful. I've checked the back to see if it's shorting on something. But haven't seen anything yet. Hopefully this sunday i'm gonna check the fusebox with the testlight to see if it's a short.

[Plumcrazy]

Unplug the front and rear harnesses and see if the fuse still blows.  If not, plug each harness back in separately to see which one blows the fuse.  Then you will at least have narrowed down the problem to one area of the car.

If it stil blows the fuse with both harnesses unplugged then start tracing the circuit back to the fuse.  If you can unplug other items off that circuit try that also.

[Charger4404spd]

Unplug the front and rear harnesses and see if the fuse still blows.  If not, plug each harness back in separately to see which one blows the fuse.  Then you will at least have narrowed down the problem to one area of the car.

If it stil blows the fuse with both harnesses unplugged then start tracing the circuit back to the fuse.  If you can unplug other items off that circuit try that also.

[Just 6T9 CHGR]

Have you checked the bulbs?  Are they the correct ones?.  Its possible the small filliament of the 1157 bulb is shorting out

[68MoparCharger]

checked everything and used Charger4404spd's method and solved the fuse problem, but now the turn signals, and flashers are slow? I'm gonna send it into a shop tomorrow to have them look at that and at my heater. the heater isn't getting any juice. so i'm gonna have someone with more equipment spend their time looking at it. I think it could be the battery though, the lights flash faster when i'm at speed or have the engine revved up (Higher than idle). Or maybe there's a bad ground  dunno.