check fuse #23 (15 AMP FUSE). I ASSUME THATS GOOD COZ UR HEADLIGHTS ARE WORKING BUT CHECK IT ANYWAYS.

NO RELAY TO AFFECT PARK LIGHTS. ON THE HEADLIGHT SWITCH CIRCUIT, CHECK SPECIFICALLY RED WITH BLACK STRIPE WIRE FOR 12V WHEN YOUR PARK LIGHTS ARE ON (DO IT RIGHT BY THE SWITCH).

IF YOU DONT HAVE VOLTMETER, BUY JUMPER WIRE AND JUMP RED WITH GREEN STRIPE TO RED WITH BLACK STRIPE...
(YOU ARE BYPASSISNG THE SWITHC) IF PARK LIGHTS LIGHTS UP, CHANGE THE SWITCH. MUST HAVE BAD CONTACTS