06 mazda 6, build relay for door locks

I dont think you are going to need relays...Just follow what i posted...______________________resistor_____________ then to lock/unlock in car

So cut the lock wire...put one end of resistor on one side of cut lock wire...the other end of resistor to the other cut lock wire...Now attach it to the single wire door lock system...ARE they just negative outputs on that r/s for door locks...?

On the lock wire sectionof your R/S are there two wires or six? If two you wil need relays, if 6 the relays are inbuilt and follow Tommy's post.

If two wires, wire as follows:-

Lock wire relay 85  constant12v+ to 30 and 86 via a3amp fuse, 87 via your resistor join with unlock to vehicles lock/unlock wire.

Unlock wire, might work direct but suggest using another relay and joining to 85, same power feed as lock to 86 and 30, 87 to vehicles lock/unlock wire joined with lock wire.

If 6 wires they will be marked thus. Lock n/c, lock n/o, lock common Lock n/c not used, lock comm on, to ground, lock n/o to vehicle's lock/unlock wire via your resistor.

Inlock. Unlock n/c not used, unlock common to ground, unlock n/o to vehicles lock/unlock wire.

Are you sure it's neg via a resistot to LOCK?  Every other vehicle with this system, e.g. Euro VWs has straight neg to lock and resistive to UNLOCK.

Check.