3rd brake light dimly flashing - killing battery?

[Lenair]

This is driving me crazy. My 98 XLT has a new alternator and a new battery but it still won't keep a charge. Everytime I need to drive the truck (it's a 2nd vehicle) I have to jump start it. The battery stays charged for about a day. The last time I drove it, I parked forward in my driveway (something I rarely do) which made me walk around the back of the truck. That's when I noticed my third brake light was flashing. The strange part was it's almost so dim I didn't catch it. Does anyone have any idea on this one? I'm afraid to drop it off at a shop with little more than this to tell them.

 

[Turdle]

My third brake light also does this, however, only after I installed LED's in all the other tail light sockets. Do you have led tailights installed?

I haven't had a problem with a dead battery though, unless it sits for a week or so.


I also noticed the flickering turns to a steady glow when the PATS is set ( doors locked and horn sounds)

 

[Lenair]

I haven't installed LEDs in the other lights but I you got me thinking about the other brake lights so I checked them. Both bulbs were burned out so I'll replace them and hopefully this will solve the problem.