In my '86 240 I recently installed a remote locking/alarm system so I can unlock the doors remotely. The car already had a central locking system but I had to install a driver's side actuator in the door to make them all fully "power locks".

During my research I saw an aside somewhere that the same type actuator can be installed in the trunk (so I bought two of them) to be able to lock/unlock that as well via the power locks or the remote.

Now that I'm ready to do the job I can't seem to find any info on it anywhere.

Any previous threads, guides or videos anyone can point me to for assistance on this? Tx.

 

Our 87 had a trunk lock actuator from the factory, but I never had to mess with it.

 

The power locks should all work off the main control you installed in the driver's door, if all is correct. The trunk is on the same circuit so you should have an actuator there from the factory. I believe that trunk lock has three positions, always locked, always open and the one where the system is operated in concert with the door locks.
If the trunk lock doesn't work with the rest of the doors something is wrong with the factory actuator that should be there.

 

IIRC, turning the trunk key to the right, and removing it while its horizontal hard locks the trunk. if you remove the key when its vertical, then its soft locked, and can be unlocked electrically.

the 940's mostly have actuators on all doors and can be locked/unlocked from either front door or the trunk.

 

ok, here's the parts diagram for the trunk lock on a 240 sedan... The wagon is quite similar, the 'motor' is over to the right of the latch. on both of them, the wires to the motor go through the LEFT hinge, then down to over the left rear wheel hump and forward to under the left side B pillar, the trunk motor wire joins the left rear door motor, then goes across to the left side of the driveshaft hump, where it goes forward to the center console and up to connect to the door relays that are behind the center console just below the center A/C air vents. there'a a pair of relays, one causes all the motors to 'lock', and the other to 'unlock'.

 

I opened up the upper trunk latch area today and the actuator was indeed already there, BUT the rod that connects it to the lock was disconnected. Not sure if the previous owner was having issues with it and purposely disconnected it or if it fell out over time.

So I pulled all of the parts out, put a little WD-40 on the moving parts, reconnected the rod (it popped in nice and snugly) and all seems to be working correctly now with the full power locks and remote locking system I installed.

The horizontal "hard locking" works as well. Tx...

 

WD40 is not a good lubricant. its handy for cleaning stuff up, and will lubricate for a short time, but its just basically kerosene with a little bit of very light oil. for places where small amounts of light oil are suitable, I often use Triflow (or ATF). for places like those locking levers and such, I'll put a little dab of green marine grease on the contact points.

 

Good to know, I just ordered some Tri-Flow...tx!