On a bit of an impulse one damp morning, I decided to investigate the
switches in the driver's door armrest, with particular interest in how
resistant to incident water they might be.
They sit right under the window, which may often be open, and even a small
opening at the top is basically positioned right over the switches.
I usually drive with the side windows open, even if only a little bit,
as my ears to the outside -- even in most rainy weather unless it's
*really* pouring down.
On the Kona, there's not really much lip of A-pillar metal at the left side of the windshield, and the wiper tends to fling water right off the edge where it then hooks around in the airflow and drops in on the armrest. The Prius has similar behavior although not quite as bad, and its switches never seemed to have any issues from minor water incursion. Since many vehicles have a similar setup, what have manufacturers done to guard against the electrics underneath getting soaked from a window left open, either while driving or stationary? The only way to really know is to take a look.
|There is a single screw under a small panel at the bottom of the grab handle, and the rest of the inner panel is attached to the door by typical plastic snap-pins that friction-fit into holes in the door metal. In a new car, they're very tight and care is needed to not break them despite the need to pull on the panel pretty hard. It often helps to peek in with a flashlight and get a visual on where the next pin is, and fish a large flat screwdriver or "snake tool" in next to it and pry apart gently. Work slowly around the panel to pop one pin at a time. Sometimes they break anyway, but losing one or two isn't a big deal.|
Sometimes the pop-pins pull out with the panel, as they're supposed to,
and sometimes they slip out of the panel slots and stay in the door
They all need to be attached to the trim panel side before reassembly.
With all the pins finally released and a couple of electrical harnesses disconnected, the panel is floating in midair but still tethered by the pair of latch and lock cables. Now what? It seems like you'd need three or four hands to hold all this in place and work on detaching those.
|Fortunately, both cables end in a single quick-release fitting that pops right out once a small lock barb is pushed back.|
The panel fully detached.
That wasn't so hard after all ...
Note the flexible clear plastic sheet and bead of black sealant all the way around underneath it. This is an essential part, especially in this car.
|One odd thing about the Kona that doesn't seem true in other cars, is that the weatherstripping at the bottom of the window on the outside does *not* bear against the glass as it slides up and down. There's actually a gap there, on all the moveable side windows, which prevents the gasket from being able to "squeegee" the water off the outside by simply lowering the window. While the outer weatherstrip flange is not designed to be a watertight seal to begin with, at least it's usually designed with light contact against the glass to deflect most of the water away. The assumption is made that *some* water will always leak down inside the door and exit the weep holes at the bottom, and items like the window regulator are generally designed to not be greatly affected by moisture. But having a free-flowing gap there just doesn't seem right. I double-checked that the weatherstrip was clipped on correctly on all the windows, and it just seems an inherent fault with the Kona body.|
As a result, more obvious after the previous night's rain, some quantity
of water can accumulate on the exterior side of the plastic membrane.
The membrane, with its "goop" sealant and the oddball extra bit here to
isolate the bump where the bottle holder in the door pocket sits, is clearly
vitally important to keep intact because there *are* some water-vulnerable
parts on the interior side.
If the door interior needs to be opened up to service a regulator or the like, the seal should obviously be reworked afterward.
|A few screws and barb clips release the switch modules from the armrest, and closer examination shows that the switch blocks are definitely designed to be unaffected by water arriving from above. The switch handles are cap-shaped to fully cover the plastic flanges they attach to and the operating mechanisms, and the pivots are all plastic. Each upper housing is all one molded piece that extends all the way down, with slopes built into the top so water would flow right off and never pool. Even the screw holes have generously high bosses around where the screw comes through from underneath, so water really has nowhere to go except off the sides of the assembly. Underneath, the electrical connection is shrouded by a skirt that won't let water get anywhere near the connector pins.|
The armrest and remainder of the panel is just a plastic shell, unaffected
Conclusion: High confidence that these assemblies are well designed to be weather resistant. As long as gravity continues to suck in the correct direction, water is very unlikely to get into any of the vulnerable parts of this.
When I posted this original door-teardown to InsideEVs,
if I could figure out how to non-destructively remove the B-pillar trim
It isn't difficult; the key to any trim removal around the door openings
is that you have to un-seat the rubber door seal along the edge over
enough distance to expose the edges of the interior trim first.
The weatherstripping channel interfaces with hooks on the trim pieces and
helps hold them in tight.
Once opened up, it's fairly obvious how to fish a pry tool in and go after
This shot illustrates where they are in the panel, to serve as a guide.
A strong flashlight [and appropriate optics if needed] in through the gap
between the pinch weld and the edge of the panel helps locate the pins
and where to insert the tool and pry apart.
The lower ends are also tucked under the door-sill pieces, but those are easy
to pop out, and the seatbelt passes through a hole in the panel so it has
to ride along with movement.
At the time I didn't go after the upper panel because I needed to put this back and drive somewhere, but made the assumption that almost all the interior plastic is mounted in a similar fashion and it wouldn't be hard to figure out.