Yaris Mk1 2002, UK. One door-locking actuator not working.

[cliverlong]

Hello.

The rear near-side door lock actuator does not work (open or close) when opening or closing the other doors. I have taken the door card off and unplugged the electrical wire to the actuator. From what I have seen on Youtube about the general operation of these actuators, a 12 volt supply is always sent to the actuator and with a very clever arrangement of gears, cams and electrical wiper contacts the motor in the actuator either opens or closes the lock depending on the polarity of the electrical supply. The wiper contacts inside the actuator ensures no voltage reaches the motor when the actuator/lock is fully opened or close. I have measured the voltage on the plug to the actuator when unplugged. There is no voltage measured at the plug when any other door is opened or closed. All other door locks open or close together and the 25A DL (door lock) fuse is fine (if it was blown none of the actuators would work). Now, would I expect a voltage when the supply wire is unplugged from the actuator or does the supply wire need to be attached to a working actuator? I don’t want to buy a new actuator if it is an electrical supply problem. Is there anything else I can check to try to focus in on the problem?

 

Thanks

[flash22]

it will only be a 12v pulsed supply when the doors are locked/unlocked

[cliverlong]

On 9/2/2024 at 12:57 PM, flash22 said:

it will only be a 12v pulsed supply when the doors are locked/unlocked

OK. Useful info. I have taken a chance and bought a new actuator - which should arrive in a few days. I have left open access to the rear door "internals". When the new actuator arrives I will be able to easily plug it in the socket and test it. I will post up a picture if it works. If the new actuator works I will try to carefully take the original apart (I know there will be lots of cogs and cams) to try and see if the problem is obvious.

[flash22]

a very common failure on the Mk1, they dont age well

[cliverlong]

On 9/2/2024 at 12:57 PM, flash22 said:

it will only be a 12v pulsed supply when the doors are locked/unlocked

I bought a replacement actuator, managed to wiggle the old lock out of the door panel, fitted new actuator and it seems to now open and close the lock along with the others. The retaining clip on the power supply plug doesn't engage well with the socket on new actuator - so I will put a small spot of plastic glue on the plug tab just to hold the actuator in place but it can be removed when needed.

 

Edited September 11 by cliverlong
Loaded jpg version of images

[cliverlong]

A few little tips on doing this job. Remove the screws that hold the rear window-glass guide to the door frame. The glass guide is made of plastic but will bend if pushed slowly and carefully. This will create enough space to drop the lock and actuator out of the space in the door frame at the bottom.

Also make sure you understand clearly how the metal rod from the "lock" button that pokes out through the door card attaches to the lock. There is a slightly bend in the rod at the lock and this needs to locate in a hole behind the retaining clip at the lock. The clip swivels down and holds the metal rod securely in place. See picture below.

Also there is a clip on the door card positioned just below the gasket on the rear quarter light window that can be very fiddly to locate. There maybe a trick for this that I don't know but I had to use the door card to push up the thick gasket while pushing the door card into the door frame. Once the clip was was located in the door frame the card "felt right", the top of the door card fell into place and the lower part of the card could be pushed easily into place. When this clip at the top of the door card wasn't correctly in place the door card would not locate flush with the door frame and helpfully fell off to tell me I hadn't done the job correctly.