Frozen 2009 Tailgate

Hi everyone. I was reading this forum for quite a while now and decided to register finally to be able to contribute too.
This is my first post here.

On my 2009 B200 I had the same problem last winter when we had a few nights below freezing. And my car is parked outside all the time. There is just a small (sealed?) electric switch under rubberized button (the thing you push when grab the chrome bar in the middle). It wouldn't unlock the hatch until thawed later in the day. It is truly 'fly-by-wire' setup and I don't see how you can make it totally mechanical without installing some linkage between that handle and the lock.
The lock on the tailgate seems to be activated by a solenoid, I don't understand why not to add a button on the keyfob or somewhere inside the cabin to unlock the tailgate.

Also after pulling that chrome bar too hard so many times (my bad!) it started to loosen and finally it could just pop out and separate from the hatch. I had to insert it back and then pull towards me and UP to open the tailgate. When I unscrewed 4 torx (T20) screws holding the chrome bar there was 4 plastic square clips where these screws screw in. They didn't have any decent 'flaps' or anything to hold them in place and prevent popping out. Small design flaw leading to switch flooding and grab bar separation. I cleaned up all of the area covered by chrome bar, then sanded around clip holes and clips themselves and glued those clips in using flexible epoxy (3M DP105) to absorb vibrations from slamming that tailgate shut. I made sure I epoxied those clips on outside and also around inside part of them, so it will be extremely hard to pop them out now. I inserted a wooden stirring stick with a dab of epoxy through adjacent openings to apply epoxy around clip 'stems'.

Then it was time to take care of chrome grab bar assembly. It has intricate shaped rubber gaskets all around but because of loosening of those plastic clips it didn't seal between the bar and car's body and was getting mud and water inside, it was quite dirty, even inside lic plate lights lenses. So I cleaned all that religiously with small paintbrush and soapy water. Then I dried all up and applied silicone grease on all the gaskets and replaced lic plate bulbs just in case - these are only accessible when you remove whole bar, you can't remove only the lenses from outside without breaking em. By this time my dead-epoxyed clips cured so I re-installed the bar assembly back now making sure there is tight seal with lubed gaskets against car body so that no water can penetrate and freeze the switch. Looks like it is important to have those plastic clips to be deadly attached to the door otherwise they will unavoidably loosen and allow water leaks inside the grab bar. Make sure you connect two electric connectors before mounting the bar - one for lights and one for the lock switch. I also applied some anti-seize on those 4 torx screws before fastening.

Hope all this helps and you can do the same to prevent freezing of your dooor lock. And loosening the grab bar

Cheers

My goal was to share one of possible fixes for that water in the switch problem. Sorry if my solution was already mentioned, didn't think it may hurt to read another B-owner's experience.
I didn't find where was the same solution mentioned though. Probably didn't search the forum hard enough. All I found was going to dealer and replace it with mechanical link to the lock. That's more expensive and time consuming.

I just shared what I did to fix this water leak problem and warned other B-owners not to pull that hard on the handle - squeeze the button with your thumb on the grab bar first, and then, after you hear the click of solenoid - pull gently. I was grabbing and pulling simultaneously, thus blocking the solenoid action and applying more force than it was needed. That led to popping off the clips and increasing the gap where water could leak.

Thanks for epoxy recommendation, haven't heard of it.

Update: checked the epoxy data sheet and description. It is surely very strong but not that flexible after cure. There is a lot of vibration when you close the tailgate which may lead to flexing of joined parts and flaking that epoxy off. That's why I think it's better to use flexible epoxy. I have access to different 3M epoxies so I can choose from several, including same 'high strength structural' ones. DP105 seemed the best for this case. Will see how it goes with time. Did anyone else epoxied those plastic clips holding the grab bar on tailgate?