Mazda CX 7 R/S Locks And Disarm

I've done this car, I only used a relay for Lock, with the resistor of course. Unlock went straight to the wire. Same with the arm/disarm wire. I didn't try it with out the relay on lock. To test, I use an analog multimeter. The lock wire will make the meter's needle move when pressing lock/unlock button on the drivers door panel. It will go to 12volts when unlock is press and probably around 5 volts when lock is pressed. For the arm/disarm wire, you will be testing while turning the key in the drivers door key cylinder outside the car. You will get the same results on your meter as above. 12v for disarm, and about 5 volts for arm.

See, now I've done one and neither lock, unlock, arm, or disarm worked without relays. I have a feeling it's one of the border line ones where sometimes it will work and sometimes it won't. Since you have to put a relay in for lock / arm, you might as well use one for unlock / disarm.Kenny

Owner / Technician

KKD Garage LLC

Albany, NY 12205

You might be right flobee, it's just that the first time I did this about 10 years ago on a VW Polo, 1Kohm, I seemed to need relays both sides.

So OP I actually posted before Kenny but they had to airmail my reply across the pond! Conflicting advice, all given by experienced installers, Flobee says not needed, Kenny and I say it's needed. Wire it Flobee's way but have a spare relay in case and let us know!

Working at a Mazda dealer, 95%+ of my installs are Mazda. With a CM6200, I have NEVER needed a relay for lock/unlock, and NEVER have had a problem.

If you want to use a relay for peace of mind, that's perfectly fine. I'm just saying based on my experience with Mazda, a relay isn't needed.

No relays, so not even diodes to prevent feedback on the wires?

No relays, no diodes. Straight connection from R/S for unlock. Straight connection trough resistor from R/S for lock. I'll splice the unlock wire into the lock wire, after the resistor of course, so there is one single wire connected to the BCM. Don't need to fool with the GREEN/ red wire on the BCM, just the BLACK/ white.

The BLACK/ white is in the bottom connector on the firewall facing side of the BCM. It's a corner pin on the connector, so it's that much easier to find.

some alarms outputs are just more powerful than others. it has nothing to do with the car's need for a relay.

This is true. I use only Compustar products. I have heard of issues with Directed remote starters having problems with things like poor/weaker triggers.

Amongst loads of other faults.