When the automobile comes up to normal operating temperature in park and the coolings fans engage, the exterior parking lights come at the same time and the lights go out when the cooling fans stop? I am stumped.

"2003 Accord 3.0L EX Coupe AT"

 

They share common grounds, G201 and G301. These are behind the headlights. Someone may have loosened or disconnected them for some reason. This might cause the problem you see.

You need a shop manual to run this down. Suggest automanualsource on ebay for an emanual ($21.99).

good luck