Hi I need help. How can I tell if the turbo is working or not. I pull a 35 ft gooseneck LQ horse trailer. Going up a hill the speed will drop down to about 42 and it will go it a higher gear but the speed will only get to about 50 then kick back down. When should the turbo kick in and how will I tell . PLEASE HELP

 

Turbo does not "kick in"...

How heavy is the tralier?

Do you pull with the OD locked out or not?

How many miles on the truck and any mods done to it?

Any work done to it ever?