A) Create a vacuum of 285 mm Hg on the switch. (or more).
b) Measure the resistance between the terminal "1" and switch housing.
- Resistance: about 0.7 ohm at 20°C
If the resistance is not as specified, replace the fuel heater assembly with the vacuum switch.
2. Checking the conductivity of the switch.
Use an ohmmeter to check for continuity between the terminal "1" and switch housing.
If there is continuity, replace the fuel heater assembly with the vacuum switch.
3. Checking the operation of the switch.
A) Create a vacuum of 285 mm Hg on the switch. (or more).
b) Use an ohmmeter to check the continuity between the terminal "1" and switch housing. If there is no continuity, replace the fuel heater assembly with the vacuum switch.