Relay Problem

I was wondering if anyone could help.  I am working on a 1994 Oldsmobile Cutlass Supreme.  I did the strobes in the rear parking lights, the owner of the car wants the lights to go of when the strobes come on, I tried doing this with a relay but had no luck.  The 85 went to ground, the 86 to the srobes, the 30 to one side of the parking light wire in the back and the 87A to the other, yet I still have juice from both 87 and 87A, any response will be helpful, thank you. kg85

yea that works because it is a starter kill setup and 87 not usedand ass long as the lights are on pin 87a should have power , pin 30 is the one that should not. when the strobes are turned on when you shut off strobes pin 30 should have power.