Aaron, while you're here, I had another duraspark question for you. I'm working on my sister's 83 mustang 3.8 and I notice that the duraspark module has an extra pair of wires running to a vacuum switch/sensor mounted to the fenderwell right next to the module. The switch looks just like the 10"/4" switches jeep used for the computer controls on the BBD in the 80's.
What is the function of this circuit?
thanks again, Brendan