G’day

I want to install a 1983 e-bay sourced 240 turbo boost guage in my normally aspirated 1990 240 to act as a vacuum guage.

Front seat passengers will be told that I only take it into the red zone when I am on a race track. ;-)

Anyway, the guage itself seems to be mechanical, as I can make the indicator needle move nicely, without any electrical connections, when my lips and lungs simulate an intake manifold connection.

The black and brown wires are I think earth and dimmable power connections for the internal guage light bulb.

However, I can't figure out what the blue wire on the guage is for. The Bentley wiring diagram for the 1983 turbo 240 shows that it connects to an "instrument panel connection", but not where it goes after that.

There is no such blue wire in the diagram for the 1985 model turbo boost guage.

What does the blue wire do in the 1983 guage? Do I have to connect it to anything?

Thanks guys. I have found the archives and FAQ’s very helpful in regard to installing accessory volt and oil pressure gauges.

Tassiebrick 1990 240 Wagon 185K kms