Mazda 3 Door Light Stays On & Alarm Fix 

Heya Steve, glad to be of assistance. Edited the title :)

yes always best to test the function before assembly. glad its resolved :)

Glad it helped Hanna :)

glad to help :)

I dont usually make video unless completely necessary. This was definitely one of them. I found no similar video on teaching people to fix such a simple fault. And i knew it was plaguing almost every mazda 3 owner. So i just had to post it up. Its a lovely car and simple to maintain. A new actuator is simply unneccessary and a waste of money. Glad to help bro 🙏🏽

Give it a go mate. Definitely worth a shot.

Does your model come with a display screen? If it doesnt. Then the only way is to jump the wires on each socket on every door till the door light goes out to test which is faulty. The reason the key fob doesnt lock is because if any of the door is sensed to be open. Automatically disarms the feature to lock.

Heya, if i understand the component correctly, it is actually not grounding out which is why the light stays on. It goes off when receives proper ground. Dont quote me on this though. Prior to this fix i was running some test, i attempted to ground one of the wires from the actuator socket, IIRC green and black and the light went off. Again please becareful when doing what i did and double check those wires are not receiving 12v when testing.

Pretty sure my immo red led light used to blink all the time when its armed or disarm. as long as it goes off while driving and the car starts up fine. your immo is working as it should.

If the door light is coming on when all doors are closed/shut then yes this is the fix

@@Dev4663t I managed to fix it by repairing the connectors on PCM - they were rusted...

@@pavelsmetana5133 BCM controls the interior

that yellowing is actually grease taht helps keep the gears lubed. i wouldnt clean it off unless yours is black and grimey. if its clean and yellow, best to leave it as it is

When the door is reading as unlock, you cant arm fob. Other than that my fob has no issues

That's a common problem with the door lock actuator. The motor inside that turns the gear to lock/unlock wears out. Usually the drivers door to go first. If none of the doors will lock with the fob then its a BCM issue

I had two problems, one being intermittent passenger door ajar warning and secondly central locking would not lock which happened when a door is recorded as being open due to the faulty brush terminals not contacting or the door actually is open and informing the central computer not to operate the central locking as a door is open. Both of these problems have stopped since cleaning up and bending the brushes down to make better contact which is not too difficult once the 'sealed for life' box is opened and re-sealed with a thin line of super glue. It has been working okay for a while but never know when the fault may return and it is a cheap fix if you don't buy a new actuator lock box.

@@alanchappell4845 That is a proper fix you did. Cleaning with an abrasive, some IPA and then a light coating of dielectric grease before re assembly is what i do. I also replaced the motor (Ali Express) in mine since it was having problems with lock/unlock. I also found out my alarm was going off on sunny days. Turned out to be the hood closed sensor (switch). I disconnected it and then there was no more problems. Until a week later I noticed my battery would run down while the car sat for days. Figured out the computer was constantly sending power to that circuit because it was seeing it open. I soldered the wires together to close that circuit and stop the current draw on my battery.

Getting drained could be related if your dome lights are on and you leave the car parked for a long time. It could definitely lead to a parasitic draw and kill the battery. But not overnight. Probably weeks.

@@Dev4663t lights out without key in. just wondering if light on could indicate a short somewhere. Also won't lock from fob. will unlock so not fob battery.

@@Electric666s hard to say mate. Dont quite understand what you mean. If you suspect a short/parasitic drain do the test of using a multimeter and pulling out fuses.

@@Electric666s ive explained on your other comment why you cant lock. If your door sensor is saying a door is open. Your fob wont lock. You gotta first fix the door issue for the fob to be able to arm your alarm.

the display screen on your dash that displays your fuel economy etc, actually shows which door exactly is opening up while driving.

The 1st generation Mazda 3 will not show you which door is open unfortunately.