The lights are controlled by the PCM. There is a plunger type switch in the diff that is either off or on depending on the locker state. It's really weird that both are flashing, that would indicate to me there's maybe a common wiring issue somewhere. Check the output of the switchs at the pumpkin - I think it presents a ground to the PCM when the locker is engaged. Once you determine the switches are indeed following the locker activation you can trouble shoot further upstream.