boot/Trunk won't open (Volvo S40)

in this video I check out a Volvo with a boot not opening problem. I decided to make this s a more in-depth video on the situation to help out a question from a viewer.
thanks for watching.

[@intelligentauto737]

Diagnostics at its best, understanding how it works makes finding the fault so much easier. Great work fella

[@mechanicmatt871]

Aye it definitely helps when fault finding. Thanks for watching

[@SimplyDiagnostics]

Great walk through video. Thanks for the support and modelling my t-shirt Matt, it looks significantly better on you. You're awesome 🏆

[@mechanicmatt871]

Thanks Steve, I'm happy to pass on anything that can help someone wanting to learn.
Thanks for watching, you're awesome mate.

[@davesterl]

Excellent stuff Matt, love the whiteboard

[@mechanicmatt871]

Thanks Dave, I thought it may help someone to visualise what I was doing at the car.
Thanks for watching

[@johnbickle4654]

Great tutorial matt thanks , seeing the schematic diagram made it easier to understand how it works thanks again.

[@mechanicmatt871]

I thought this may explain your Mondeo better in this video better than if I wrote it.
Thanks for watching

[@evansmarts775]

Excellent video Matt you gotta do this more on white board ( I am drawing as watching it and making it sense out of all this ) awesome please do more like this to be honest majority that I know have issues reading proper wiring or understanding how it works so please do more like this 😎 thanks again loved it

[@mechanicmatt871]

Thanks Evan, thanks for the feedback on this. I'll try to make that board a thing. Thanks for watching

[@ianhenderson4441]

Nice work Mechanic Matt, intresting seeing the power probe identifying duty cycle ,,,,,,,

[@mechanicmatt871]

Thanks Ian, aye it's helpful as a guide to see the different lights flash. Thanks for watching.

[@edmondsollaku6535]

Great Video Matt your best in my opinion, excellent understanding of the system. Thanks for sharing 👍

[@mechanicmatt871]

Thanks for your kind words, thanks for watching Edmond

[@rollingtones1]

8:50 It becomes the ground side BECAUSE the bulb filament is a LOAD. If the bulb filament did not have significant resistance (if it was just a wire) there would be no RESISTIVE LOAD.

[@mechanicmatt871]

Exactly, in the boot latch case it isn't a bulb. I just used it as an example to explain where the 12 volts has gone. (Ground side switched) remember even with a load it will have power at both sides of the bulb when the switch is open on a ground side switch, although it won't have current flow obviously.
Thanks for watching

[@ehombie]

just subscribed! thanks for your video(s) and expertise.

[@mechanicmatt871]

Thanks for watching and subscribing, your support means a lot. cheers Matt

[@nemocap2958]

Great tutorial! Thanks!There is a micro switch in the lach mechanism which is responsible for lights in the boot and dashboard notification "boot is open". Anything else?I have no lights in the boot and it drives me crazy.Found that micro switch but not much can be done than buying a whole lock!!!Very frustrating!

[@TheGibby3340]

Nice work Matt 👍

[@mechanicmatt871]

Thanks mate

[@tennisfitapp]

Hi Matt, we have a Volvo V50 and problem is that boot wont open when trying to open it manually with fingers on the back of hatch - but then when I start engine suddenly I hear boot opens. Also opens when I click on my keys the “yellow” button so then I can open it but its really weird as otherwise wont open and again opens when I stop the car and turn off engine -
Opens again… any recommendations what this could be - started to happen recently…

[@mechanicmatt871]

I once had something a scenic that was like that. Boot only opened with the engine running.
Turned out to be a deliberate bypass on the fuse box to stop a battery drain.
Not saying that is what's going on with your car, just a thought

[@lponm]

I have a similar issue. The switch on the trunk also works in key position 2 or II. Engine doesn't even have to be running.

[@nelsiebitch]

🤤 your accent

[@mechanicmatt871]

Thanks for watching

[@Juventino6]

3:06. I have only 3V and the latch not open. Do you know what is the reason?

[@mechanicmatt871]

It's a possibility voltage drop from a bad wire in the boot hinge area

[@oOMetalManiaOo]

Great video, i have the same problem with the add that my volvo s40 gives a warninglamb that my trunk is open, while the trunk is closed and cant be open, what should i do to open the trunk to be able to change the wiring which is cheap to buy and less hassle comparing to restore the wiring, would appreciate answer🙏🏼🙏🏼🙏🏼🙏🏼

[@mechanicmatt871]

Can you bi directionally open the trunk with a scan tool? Or is it possible to lower the rear seat backs in the S40? It may be that the switch in the handle is working but it won't actuate the trunk latch because it thinks it is already open.. this could be a pain to open.

[@oOMetalManiaOo]

No i cant open the trunk with a tool but the rear seat can be taken down, yes the car thinks the trunk is open since the constant warning but i can crawl in to the trunk and my question is can i open the trunk from there doing what you did in the video?

[@mechanicmatt871]

Yes you will have two of the wires going to the actuator. It will need a power and a ground. If you can crawl into the trunk and remove the trim to get access to the latch. They may be slightly thicker wires than the other wires. There may be something in this video that could show you the wires.

[@oOMetalManiaOo]

@@mechanicmatt871 ok thanks, i have an appointment with Volvo this coming Friday, do you think changing all the wire set for the trunk will solve my problem or could my problem be something else than the wires?

[@mechanicmatt871]

Always the chance it could just be a faulty latch with a micro switch fault but usually it's a broken wire