i have seen guys that can bypass the **** (even on factory equipped vehciles) to where the fogs are on when the engine is on... regardless my fogs are one when my engine is on (since i always put them on) and they don't burn out, so it sounds like the previous owner did a bypass and messed it up which is why the are burning out like you had mentioned...

 

that's basically what i'm thinking, that the previous owner used wiring that might have been too small and causing an undervoltage condition, or another problem.

Like I said, see if you can volt meter both sockets and compare to battery volts.