Fitting Central Locking

One update which is well worth it for a car in daily use is central locking.  It's so easy to forget to lock a rarely-used door so being sure that all doors lock with the driver's one is a useful security measure.

Maplin Electronics do a full kit for four doors at £24.99 so I decided to take the plunge and fit one to Sheila.  At this point it's worth mentioning that it's designed for 12v systems but the actuators seem to work perfectly well on Betty's 6v electrics.  Not sure if the same's true of the control box but it should be relatively easy to convert.

The kit itself is very comprehensive except for one small point.  They provide 4 rubber grommets to feed the wiring into the doors but you actually need 8 - 4 for the doors and 4 for the door pillars!  Still, that's a minor point given what you do get - 2x 5-wire actuators (for the front doors), 2x 2-wire actuators (rear doors), all mounting hardware, the control box and a ready-to-use loom:


Contents of the kit


Fitting is fairly straightforward but may take a little thought about how to connect the actuators to the locks if they're an unusual layout.  But more on that in a bit!

The first step is to remove the door card:

Door card removed


and then to mark where you want the actuators to go.  The important bits here are to try and have them working in as close to a straight line as you can, and to position them where they won't foul anything else - including the window and winder mechanism, so be sure to check the window in several positions:

Marking actuator position


Once the position is decided, drill two clearance holes for the included self-tapping screws and fit the actuator in place:

Fitting the actuator

Actuator fitted to door


Now you have to connect the actuator to the lock mechanism.  The kit comes with control rods and clamps that are designed to clamp to the existing lock rods.  You can adjust the action by moving the clamp on the rods until it works smoothly.  You may need to bend the actuator's rod to line everything up:

Fitting and adjusting the actuator rod


At this point you can test the operation on the door using a "flying" live lead from the battery.  Connect 12v+ to either the green or blue wire and touch the other one to earth briefly.  The actuator should move to either the locked or unlocked position.  Swap the blue and green wires around and try again - it shoud now move immediately to the other position:

Tesing the actuator control


This is where a problem showed up with Sheila.  Her locks are a little unusual in that there is a single control rod which operates both the lock and the door catch.  This meant that, with the actuator adjusted so that it could work in both directions, it not only unlocked the door but popped it open as well!

A little thought and some 1.5mm rod solved the problem by reconnecting the actuator to the door lock itself.  There was a suitable slot in the lock plate to fit a small hook and use the supplied clamping blocks to fit it all together:

Modified linkage for actuator


Once you have the first actuator fitted you can either continue with the others or start to fit the wiring.  I chose to do the wiring next as it meant I could reassemble each door as I went.  The wires need an 11 - 12 mm hole in the door pillar and a matching hole in the door itself.  It's also a good idea to tape the part of the wiring that goes between the two holes so that they form a single loom:

Hole for wiringFitting loom to the door


The wiring to the actuator itself is completely straightforward - just connect the wires in the loom to the same colours on the actuator.

You now need to fit and connect up the control box.  This needs one self-tapper to hold it, an earth connection and a permanent live feed. Anywhere out of sight will be fine but make sure it's within reach of the main loom connector!  Once the box is mounted, plug the loom into it.

It's important that you find a permanent live (not one switched by the ignition) or you'll only be able to unlock the car once the ignition's on!!  The kit includes an in-line fuse for the system so you can safely wire directly to the battery if you want.  In this case, I swapped their screw-connector for a standard spade terminal and connected to the car's fuse-block:

Control box mounted under dashFind a live feedWired up!


Once you get this far you can do a "proper" test by connecting up the other 5-wire actuator and pushing its link fully in, then out.  As you do so, the door with the actuator fitted should lock and unlock.  Whether "in" is locked or unlocked will depend on exactly how your door locks are designed.  It doesn't matter which is which, as long as it works in both directions.


Once you're happy it's working, put the door card ets back and start on the next door.  This one should be a lot quicker because you've already done the control box and should have a good idea how you'll be laying it out by now.


Finally, extra / spare actuators are available so if you feel ambitious why not include your boot lock in the system?  A 2-wire actuator wired in parallel with one of the back doors should do it.

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