Boot wont open and plate lights are out

[matt79jh]

I came to open my boot today and it would not open, there is no noise at all other than the very quiet sound of the microswitch clicking.

I looked about on the internet for causes and allot were pointing towards a faulty micro switch or the loom. I had a look around as far as i could by taking the trim off the inside of the boot by climbing into the boot through the back seating area, i could'nt see any faults or loose connectors etc.

I then wondered if there might be a simple fuse problem and noticed the loom also incorporated the plate bulbs so checked those and they dont work either.

I looked through my handbook but could not find the right number fuse for the boot loom, the closest i could find was 77 but that was'nt blown not sure if this is the right fuse anyway.

I don't want to buy a part i do not need so any ideas how i figure out if its the swtich or the loom or some other problem? Im guessing its a faulty loom or fuse becuase of the numberplate bulbs also not working.

Any ideas would be appreciated

[Snoodini]

I'm 95% sure your wiring harness is broken it seems to be a common problem. You can check the continuity of the wires. There are wiring diagrams avaliable online. Here is one: http://www.volvowiringdiagrams.com/?dir=volvo/S40%20V40%20V50%20Wiring%20Diagrams

I wrote a replacement guide a couple of weeks ago here: http://www.volvoforums.org.uk/showthread.php?t=208492

[s40manbaz]

on my old s40 I changed the loom/lock and micro switch before they went lol as there all so common . yours does sound like the loom . they are £33 from Volvo worst case its your lock there just over £100

[matt79jh]

Thanks guys

The next problem i have is how to open my boot so i can get a proper look at replacing the loom.

Ive read somewhere that if i put 12v to the thickest guage wires in the connector between loom and switch it will power the switch and open it?

[Snoodini]

You will need to get to the lock mech electrical connector then apply anything between 5 and 12v between terminals 1 and 2.... if it makes a sound but it does not open then reverse the polarity, you will not do any damage by getting it the wrong way round.

[homer timpson]

Matt,

Did you get your boot sorted?

Weird, mine failed too ... on Saturday after I arrived at the golf club for the Medal!!
I was more concerned with getting my clubs and trolley out through the back of the seats than the boot issue itself :car:

Came in on Monday and was straight on here looking for solutions.

Like many others, I had a wire broken in the loom - quick attachment of some fresh wire, reassembly of components and, hey presto, one working boot again.

Hope you have success.

Homer

[matt79jh]

Only just had chance to play again with it today after a busy week. Ive just touched a 12v supply to the terminals and i hear a good solid click as if the lock has opened, but i get out and try to open it and it wont open still!!

I climb back in the boot and reverse polarity and it clicks again so the mechanism is obviously trying to opertate both ways, it sounds just like it does when i do it by key excpet the door is still shut solid

HELLPPP!!

[matt79jh]

Ok some developments...

Not sure if this was the right thing to do but its too late now anyway. The 12v was'nt opening the lock so i decided to undo the three bolts around the locking mechanism, this did the trick and i manged to open my boot. However the mechanism was still locked onto the car.
I took the screws off back off the mech and managed to open it and manually operate it to get it off.

It seems as though the mechanism is'nt functioning with the power supply, part of it operates but it doesnt flick the catch open and close.

Is this none fixable? and im guessing this will be the most expensive part of what the problem could have been!! the loom seems in tact anyway so it looks like a faulty catch?

[matt79jh]

Job Done!

I remembered that my numberplate lights were not working either and that a month ago my boot kept opening for no apparent reason so thought there must be a wiring problem too even though id pulled the rubber sheath down to inspect the loom.
However on second inspection i noticed that two wires were slightly cut through so the wire was exposed. I took the sheath fully down then two wires popped out, so i had two wires compleatly cut through and about three that were sheered through.

I twisted the wires together to test everything, and bingo the lock mechanism worked, im guessing the 12v battery i was using to operate the mech was'nt strong enough to power it, maybe low power.

Now then being a yorkshire man and needing my car boot for tomorrow i soldered the wires and taped them, then taped all the sheered wires and fully taped the whole lot to protect it. all put back together and i have a fully operational boot again with zero cost, im one happy bunny....

Thanks again for the help guys, im off to sit down now and feel proud of myself

[Snoodini]

Glad you got it sorted. The design of the loom and it's protection really is crap.