[Administrator]

Hello
for 379 requires sound pack 4
everything you have to install in the mod folder and connect in the game:

ATS_RTA-Mods_Peterbilt_379_v1.2_Part1.scs
ATS_RTA-Mods_Peterbilt_379_v1.2_Part2.scs
RTA_Sound_Pack_4_v1.0_Part3.scs
DLC_SCS_for_RTA_trucks_v1.2.scs

If you have everything installed correctly, then there will be no problems
In order to understand the reason, you can open the game log and see the errors