I have an issue with the HSI CDI when using the F1 GTN in P3DV4.1.

The CDI does not link to the GTN.

This issue occurs when I use the built in GTN interface, for the RealAir Turbine V2, or Carenado S550 II, or a custom interface such as the Carenado Citation 525.

I tested the same planes, in both P3DV3.4 and P3DV4.1, starting at PHNL, with a simple flight plan of PHNL->NAPUA->PHLI.

They do not work in P3DV4.1.

They DO work in P3DV3.4

To be clear, the Auto pilot works OK...when switching to an ils  (vloc) via the GTN... the interface between the two work in P3DV4.1.

The issue is simply linking the CDI with the GTN.

Here is a picture of the GTN set to use GPS link to the HSI CDI:

Here, we are in P3DV4.1

It does work in P3DV3.4 as shown below:

Of course, it is possible I have missed something...but I believe the issue lies in P3DV4.1.

NOTE: I have posted the above over at the prepar3d forums.

Do you have the latest update for the F1 GTN 750? Check their user forum they have some infor regarding P3D v4.1.

Thanks Martin!

After going to the F1 GTN support forums, I've tried the following from the F1 GTN support and so far, it works. Still testing the other planes...

"...re-download and reinstall version 2.04

And make sure to delete this file:
C:\ProgramData\Flight One Software\F1GPSGeneral.dat

This should fix all problems...."