Does anyone have a decent wiring diagram for the NC central locking system
I’m having a strange issue with mine wanting to lock it’s self all the time.
I found that if I remove the small connector from the drivers side central locking actuator, the fault goes away.
I can see no detrimental effects of removing this connector, everything I see is working as it should, so I’m trying to determine what this connector actually does.
The two wire colours in question are black and white/red
Looking at the circuit for both the two wire ‘Door Lock Switches’ and the one in the driver’s door actuator, each has three positions; with 1) ‘Lock’ a resistor to ground, 2) Centre position open circuit, and 3) ‘Unlock’ grounded.
If the ‘door lock switch’ is disconnected it is effectively the centre position. If it has the resistor it will Lock. It sounds like the switch is either not adjusted properly for movement, or failing inside, either way it is not fully leaving the Lock position or maybe relaxing back towards it after the initial opening.
The other possibility is that the limit switch in the actuator is not reporting correctly, but that would continue to give problems if you unplug the two wire ‘door lock switch’ connector.
See the Mellens circuits and use LibreOffice to be able to read the weirdly encoded Wiring.pdf drawing a lot better than Adobereader. (remember to swap left US and right UK)
Good luck
OK, when you say 2 wire door lock switches, I assume you mean a manual electronic switch which allows you to lock the doors from within the cabin ???
If so, then mine doesn’t have these.
Based on this, I’m not entirely sure what you mean when you say switch adjusted properly.
I’ve had the lock and actuator out again this evening, and from what I can see the issue seems have something to do with the key lock being in the neutral position.
The cam on the actuator which is operated by the key lock, rotates around 160 degrees, lets say 0 being locked and 160 unlocked.
Therefore 80 should be about central.
If I operate the cam manually to zero, the door will lock.
If I operate it manually to 160, it unlocks, however, the moment I put the cam in to the central position(80), it locks again.
I also found that if i locked the car from the outside with the key, then used the fob from there on, it appears to operate correctly, although this was only a short 10 minute test.
If I open the car from the outside with the key, and allow the lock to return to neutral, then the central locking goes heywire again.
I’m still not 100% sure what that black and red/white wire do, but with it removed, then everything appears to operate as expected, so for the time being I’m leaving it off.
Wiring colours here are from the Miata LHD US drawing, I assume they have been mirrored for the RHD UK cars.
Is it actually a (Black - Brown/White) wire pair and not (Black - Red/White)? This should be the same on the passenger door. These are operated by the interior lock button/indicator just above the interior door handle.
Or is it (Black - Grey/Red) and part of the driver’s door actuator assembly?
And then the driver’s door actuator has six wires; (Grey - LightGreen) pair for the ‘Motor’, Black for ground used by the following, (Yellow/Green - Brown/Red) for either position of the ‘Link switch’, Grey/Red for the three position ‘Door key switch’.
Passenger door has four wires; (Green/Black - LightGreen) pair for the ‘Motor’, Black for ground used by Green/Blue for one position of the ‘Link switch.’ No door key switch of course.
The voltage supplied to each Lock/Unlock switch is 5V (central position on the one for the key), and when it calls for ‘Unlock’ it should be less than 1V, and when it calls for ‘Lock’ it should be 2.5V. The resistor should be 1000 Ohm.
If the Black wire (or even the whole door) has a poor ground then it can confuse the system by the ‘Unlock’ voltage not being close enough to 0V, because of current through the ‘Link switch’ raising the supposed 0V to something else.
Good luck
The button on the interior lever is mechanical, with a bowden cable going down to the actuator.
I’m assuming that the wiring diagram is for the American market, so may not be entirely accurate for the UK models.
Looking at the wiring diagram, I’m assuming that those two wires (black & white/red (or white/brown), should be connected to an electrical switch which operates the door lock electronically, from withing the cabin. (L&R door lock switch)
I found this on an American Miata parts store, which shows evidence that such a button exists.
http://www.partsgroup.com/store.aspx?category=Miata-Electrical&Page=1
Maybe it does also on some UK cars, but not on mine.
With the plug disconnected, the central locking is working as expected. It will lock and unlock with the door key, plip or cabin lock.
It will dead lock, arm the alarm, disarm the alarm and trigger the alarm if i try to break in.
It’s going to frustrate the hell out of me though until I can find where the fault truly is, I guess at this stage, I’m leaning towards suspecting the used actuator.
If it’s working, and no smoke or disasters, then don’t try to fix it!
Just tie up the loose plug to prevent it rattling about.