One of the issues with modern electronic stuff.-----Nobody want to fix / support these items or make after market replacements !!------Old equipment that needs a bit of attention now and then is sometimes better.
You would think that some of these medical appliances / systems ( not all of course ) could have a manual back up.------Let one of kids the operate the crank as needed.
???-----These only have ONE WIRE.-----They only need 1 wire.------The ground is internal.-----I have cleaned the internal parts.-----Easy to take apart and clean.
If there is a wire from solenoid to one terminal on a coil it is likely a coil with internal resistor.----Measure voltage at the coil with ignition turned to " on " and that will tell you the story.
Well----I do not believe anything is missing at all !!!!.------That might be a provision for a temperature gauge sending unit.----I would say the CROWLEY folks would know that.
