2011 T & C with trailer pkg..... found in van the wiring harness. instructions say to disconnect the ground cable from battery....if I do this will I lose all my pre settings radio ....security...keyless start ...etc?

what happens if I don't disconnect the ground cable and just hook the plug ins for the harness?

 

OK 2011 T&C w trailer package.....wireing harnesss came with car.....in a bag....
Instructions say to disconnect the ground wire from battery....... If this is done do you lose all your settings for GPS..radio...seats...security system....remote start...and all the other things that are preset????

The harness has plug in connectors and it appears like it would be a half hour job...

What happens if the ground is not disconnected before connecting the plug ins?
thank you for your help and sorry if I was not asking the question the correct way