In our restored Harvard Texan T-6 WW2 trainer aircraft, a Fuel/Air Ratio Indicator was installed. We cannot locate the wiring diagram of this system or information for the Cambridge Scientific Instrument Co. The instrument is P/N. 11622-1 Spec 94-27992. Please help us with the required information, or the indicator's pinout and functions.
The 11622-1 is a type A-7 single-engine exhaust gas analyzer. You can see it here on page 8. The instrument just tells you if the fuel/air mixture is too rich or too lean. Electrical inputs are simple; 12vdc and ground. Any competent instrument technician can open it up and see which pin is what. But that's only the beginning... the system includes tubes and an analysis cell, and the cell is probably pretty much useless by now, if it is still installed, but you can always try your luck.