Boot lock actuator replacement

[Juddder]

The motor in the boot lock actuator in my car had seized, and was causing the Door ECU to get unhappy so it was time to replace the unit

Order a matching part from a usual TVR supplier and a 5 wire part (overkill for the boot as this only needs a two wire) turned up at £25.00

Then went snooping around eBay / Amazon and there are 2 wire ones that match exactly with the mounting holes needed for £4.00-£5.00 or £13.00 for 4 (just search for remote control central locking actuator kit)

So I'll save the 5 wire one for when one of the door actuators blows up, as I believe these _do_ need a 5 wire and use the cheapy one to replace the boot - at this price we can just chuck it and get another one should this pack-in in the future

TVR Supplier Top
TVR Original Middle
eBay cheap replacement Bottom

[LLantrisant]

i went through all this with my doors:

the original fitted actuators did not work anymore well and nowadays replacements are mostly rubbish.

why? the original ones (at least in the early cars) did not have a spring to pull them back in a definate position after they have opened the doors /boot. after some time the internal plastic gears have too much play (which the aftermarket "online" items have straight away out of the box)

with the next opening, depending how much they moved back from them selves, the stroke wasnt enough to act on the mechanical lock.
hence they did not open / release the doors ....as consequence the owners puhsed several times the mirror button...the ECU could not cope with the repeated powering of those acutators and finally the ECU burned.

now have fitted original (2nd hand ) boot release acutators fromm a Fiesta to my doors, the ones with the spring, and it works perfect.

and as far as i remember TVR was using them as well in the later cars.


for the boot it might be not as crtitical as with the doors

[Juddder]

The boot actuator lever is pulled out physically by the boot lock when the boot striking pin pushes into the lock mechanism and the downward force pulls the lock lever and thus the actuator lever

Then the actuator just needs power to pull the actuator lever back-in which in turn pulls the release switch on the lock and thus the lock opens and opens the boot

So... I don't think this actuator at least needs any clever return spring and indeed when I took the original one apart there was no spring in there either - just a motor and a gearing cog to move the grooved actuator lever

The one from the TVR original parts supplier _is_ spring loaded so that will work well with the doors as expected

Insides of original TVR boot actuator



"Lovely" TVR wiring combined with aftermarket burner rear lights that were fitted before my time



Dead motor

Edited by Juddder on Friday 28th July 17:39

[Rufus Roughcut]

Here's a diagram that came with a kit I bought in the late 90s. In the kit is a 2 wire and 5 wire actuator with a small control box, neither acuator has a return spring and they feel very plasticky. I haven't looked inside the control box, so no idea what's in there. Looks like these cheapo units have been around forever.

[Juddder]

LLantrisant said:

as consequence the owners puhsed several times the mirror button...the ECU could not cope with the repeated powering of those acutators and finally the ECU burned.

Thanks for the info. BTW - great to get experience from others who have gone though it with parts of these systems too

I think that's what happened with my Door Control ECU is that the power pull on the relay was so high it fried the trace.

Out of interest one of the things I have been contemplating that might help with this is to put in-line fuses on each of the +12V feed lines to the Door Control ECU relays with a suitably low amp blade fuse that will blow before the circuit draws too much current

Any one tried similar or thinks that the logic might make sense?

[Juddder]

Here's my labelled breakdown of the lower Relay board on my Door Control ECU where the main trace to the Boot Relay was fried from over current (?)

Hopefully the labelling helps everyone else identify what part of their ECU blows if they go through similar...

[Juddder]

So here's how I (successfully) replaced mine for reference for the future

1. Pull cable

The original actuator had a hard metal hooked rod attached to it which pulled the lock release switch using a screw tight clamp to adjust the length of pull

It feels like this was fitted at the factory and then any excess wire at the end removed as trying to refit this was literally impossible

Instead I used some bicycle brake cable with a circular stop already fitted at one end

With this looped through the eye on the end of the actuator it fitted perfectly and gave me load of room to adjust the cable as needed



Original screw tight clamp reused with bicycle brake cable (not adjusted yet)



2 Fitting the actuator

You have to do a bit of a shimmy with your hands but if you feed the brake cable through first from the passngers side rear boot opening and then grab it when it appears where the lock should be, you can then slip the actuator back into place and use a couple of suitable screws or bolts to hold it in place as so

You can see the switch that triggers the boot lock in the middle of the 2 securing bolts in the middle of the photo. The bolts that hold the rear badge on have springs on them to enable the badge to move. It's very man-in-a-shed but does work!

[red crimps used while I wait for proper crimps to arrive - just in case anyone wants to give me the usual lecture ]



3. Fitting the lock back in place

I bought a new lock from one of the normal TVR parts suppliers and when it was losely fitted it worked fine, but the boot catch wouldn't engage so I had to tigten it and move it so that the boot catch would catch

The problem then is that the new lock is tightened, because it has the release mechanism going in the other direction to the original lock, so it jams against the side of the body work and the actuator is unable to pull the lever to release it

You can see the difference between the two in the photo below

So in the end, after trying unsuccessfully to bend the release part of the lock, I used some parts cleaner and tidied up the original lock and refitted that to get it to all work instead