Cars and electrical faults

My car (Skoda Octavia Combi) is now 5 years old and first electrical problems started appearing. Oh joy. In this case, it was the trunk opening button that went faulty. The lock there is fully electronic, the button is literally just that; button that signals the computer that someone wants to open the trunk. Opening itself is controlled by the computer.

So few months ago the button started acting up, not opening the trunk occasionally. Fortunately the car key (remote) has specific "open trunk" button that opens the trunk anyway so this wasn't acute problem as it was pretty cold out yet - working with cars in freezing conditions isn't exactly the most fun one can have outside. And remote button working indicated that it's the trunk button that failed, not the lock itself.

A few weeks ago now the trunk button stopped working completely, and since it had gotten warmer outside it was time to tear the trunk lid open and fix the problem. (or I could have taken the car to the shop, they would've fixed it and charged me something 200€..)

So I opened it. Unfortunately I didn't take any photos so text will have to suffice.

I found out that the button is a separate module, on first glance quite nice and tight-looking (IP44 or so on first estimate) package. The connector (two wires) however had oxidized pretty badly. So as a first resort I cleaned it up and put it back in. And it worked!

After a week I put the inner covering of the trunk lid back in.

And the damn think failed again on the very next day. Fuck.

At this point this would get very interesting with photos, but alas, still none...

On round 1 I was hoping to avoid any major rework of systems, but deep down I knew that oxidization usually can't be fixed that easily, which is the reason I kept the inner cover off for that long - I expected it to fail. So first thing was to scrap the oxidized connector completely and solder the wires directly to the button module.

No good. Button's completely dead.

So a closer examination of the button module itself was in order. And on closer examination I found out that the button isn't even close to IP rated as a module. Don't get me wrong - when properly placed in the trunk lid it still is protected from occasional splashes by its rubbery covering, but some moisture can still get in when in car wash or such. And when the button normally is enclosed within the lid the moisture will stay in and eventually start doing some damage (as a side note, I wonder if a small heater, in range of 2-5 watts, active when driving, would help there...)

After some careful destructive deconstruction I found that the button inside (fairly bulky) module is actually tiny, 15x5x10mm rectangle-shaped microswitch. I didn't have anything close to it handy, so I pretty much destroyed the plastic enclosure and replaced it with round one with about 1cm diameter I found from my dad's junk bin (main reason for not having photos; I wasn't at home.)  New button had to be glued and soldered in, of course. New button unfortunately isn't tactile so there is no "click" anymore, but who cares, at least it works! (for now, new button isn't any better protected against moisture)

Now, assuming the car still is in working condition years from now, I can only imagine some sorry future owner opening the trunk to figure out why button doesn't work and finding the -- umm -- innovative ways I fixed this. And I imagine that there will be some chosen expletives spoken that day...