ECA 73 - No Code (Barometric Pressure Switch)
- Check for loose connectors, corrosion or damage at BP switch and ECA terminal 2H. Repair as necessary.
- Check continuity across BP switch. Continuity across switch should exist when 0-27.2 in. Hg is applied to switch. With 27.3-30 in. Hg applied to BP switch, there should be no continuity. If continuity readings are incorrect, replace switch.
- With 27.3-30 in. Hg applied to BP switch, check voltage at ECA terminal 2H. Voltage should read 0-2.5 volts. Release vacuum and voltage should increase to 12-14 volts. If voltage readings are not to specification, check for opens or shorts in wiring between BP switch Blue/Orange wire terminal and ECA terminal 2H. Repair as necessary. Go to ECA 76 .