[s-cars] electric diff-lock switch?

[dgraber460 at aol.com]

Has anyone ever tried to wire the elec vacuum switch from under the rear seat of the 200 TQ cars (part # 893-919-173) to be a remote electrical switch for the rear diff?
Every attempt I've made at powering it up, doesn't activate it. I have the wiring diagram from the 92-97 Bentley, but just can't get my non-sparky logic to make it work. Is there too much computer nanny circuitry in it to allow it to be used this way?
TIA


Dennis 
Denver