07 F150 stock halogens.

Was messing around swapping my headlights out and adjusting my retrofit that is in the works. didn't have the headlights plugged in because Iwas using a portable power supply to power up my HIDs. When I noticed that when my fogs were on the High beam indicator would be lit but dim. Once I shut the truck off and put my headlights back in and plugged the halogens in it stopped doing this.
My question is this some type of bulb out error or is this just the effect of the fogs power possibly bleeding thru some where? Hence why once I do my retro I will need to do the "bambi mod" Or is this a shorted wire?