Ford F150 - 01 screw fuse headlight delay /overdrive off fuse blowing

I've just been living with this for years but it still bugs me. On my 2001 supercrew, the fuse(5 amp) that is in the overdrive off and healight off delay circuit keeps blowing. I can replace it and it will last for a day or two and then blow. I haven't been able to tell if it has anything to do with the overdrive off or the headlights.

Any ideas????
thanks