New in this version: Krone DLC trailer support, and compatibility for 1.41

What the mod does
Mod activates reefer trailer sounds from the Sound Fixes Pack for the vanilla game trailers in Euro Truck Simulator 2.
NOTE that trailer sounds like this are not a standard feature in the game, hence this addon will come with caveats.

The reefer engine will sound the loudest when you are close to the trailer and may play after coupling the trailer.
You can hear the hum of it inside the truck but you can open the windows to hear it in greater clarity.

The volume of the sound is determined by the trailer noise slider in the Audio settings.

Compatibility

Tested only for 1.41 game version and works with reefer trailers used in the Freight Market.
Requires Sound Fixes Pack (version 21.39 or higher) enabled for this to work.
Not guaranteed to work with mods replacing vanilla SCS trailers.
Compatible with reefer trailers in the Schwarzmüller Trailer Pack and the Krone Trailer Pack DLCs.

If you want to make these sounds work with a different trailer mod, check out the modding guide here: https://forum.scssoft.com/viewtopic.php?f=201&t=299112

Caveats

1. The major caveat is that the sound doesn't follow the trailer, so once you start driving with the trailer, you will notice the sound fading away.
However, if you stay in the spot where you hooked up the trailer, you can listen to the reefer sound for as long as you want.

2. The shutdown of the reefer sound is abrupt. The sound event stops shortly after decoupling.