Starting and Heads Up Display Issue

well, let's start with what F15 is. I think it is the water separator/fuel heater?

 

what the f15 fuse for is my first question, second question is does it have any old qualcomm system wiring if it does cut them out right under the mat on passager feet known for causing a lot of issues with datalink.

 

first look if you got a plug sticking out of the back of the cab, second lift up passger side floor mat coming up from dash going to the back of truck is should be a cable as thick as your pinkie finger and it should bracnch into two different cables you can cut this or trace it back under the dash and disconnect everything. let me know what you find, if not there i could give you a few different places where they always go bad and short out datalink

 

And take pictures so we can see what you see.

 

Volvo datalink Issue main culprit is usually old qualcomm connections shorting the datalink to ground and dropping whole communication on truck if you have zf that truck wont even move at all zf is very reliant a datalink and communication.