I'm trying to install an Ericsson HCA-20 speakerphone kit to my wifes B5 Passat. We just got a new HU for it and now I want to put the kit in while all the wires are out.

The question is: Would it be OK to wire the +12v and switch 12v from the phone kit to the +12 & swithced 12v of the HU? I'm thinking that it won't make a difference because they're still separate circuits (parallel) but please correct me if I'm wrong.

What is the power requirement of your speakerphone kit?

current can be drawn through that circuit when I get home.