Adding a cover to a truck

[Bear_from Oz]

Hello all. I am trying to add a cover to a Ural grain truck but it won't activate.
In the moddesc, I have
<type name="URAL_tipper" parent="carFillable" className="Vehicle" filename="$dataS/scripts/vehicles/Vehicle.lua">
<specialization name="cover" />
<specialization name="NewConfiguration"/>
In the xml, I have the standard cover opening command
<cover>
<coverConfigurations>
<coverConfiguration openCoverWhileTipping="true">
<cover openAnimation="toggleCover" fillUnitIndices="1"/>
</coverConfiguration>
</coverConfigurations>
</cover>
The animation sequence is standard and I proved it by connecting it to the fold command and it worked fine (covers disappeared exactly as they should). The cover just won't operate.
It seems like the cover command is just not reaching the xml and I'm stumped.
Does anyone have any tips and tricks I can try?

[Bear_from Oz]

So after a hundred hours working on this thing, it turns out that the truck files are to blame.
Something in the i3d, xml, moddesc, whatever, is disabled/blocked/turned off/screwed up/missing/locked and the truck will just not work from a new configuration. I can add all the new configs I like, but none of them will work.
I did something I should have tried about a month ago and used a different truck. After about 3 minutes, I have a perfectly working cover in place. Same for the next 4 trucks I tried.
So if your modding doesn't work, it might be the files are to blame