No. 1 Control Box

Remove connectors from No. 1 thermosensor, idle switch, and vacuum switch (Man. Trans, only). Connect timing light to high tension cord of trailing distributor and proceed as follows:

1. When engine speed is under 4000 ± 200 RPM (Man. Trans.), or 5200 +0 - 600 RPM (Auto. Trans.), timing light should not be on. When engine RPM is raised to more than 4200 RPM (Man. Trans.) or 5200 RPM (Auto. Trans.) timing light should go on.
   NOTE: Do not touch cord of timing light to high tension cord of leading side ignition.
2. Connect an ammeter to air control valve solenoid and check to see that current flows to solenoid when engine speed is under 4000 ± 200 RPM (Man. Trans.), or 5200 + 0-600 RPM (Auto. Trans.). When engine speed is raised beyond 4200 RPM (Man. Trans.) or 5200 RPM (Auto. Trans.), there should be no flow of current to the solenoid.
   Fig 1: CHECKING NO. 1 CONTROL BOX (AIR CONTROL VALVE)

   Courtesy of MAZDA MOTORS CORP.
3. Using a short piece of wire, connect both terminals of the No. 1 thermosensor connector terminal to each other in order to short circuit the connector. The timing light should go on at all speeds below 4000 ± 200 RPM (Man. Trans.), or 5000 - 0 + 600 RPM (Auto. Trans.).
   Fig 2: CONNECTOR SHORT-CIRCUIT

   Courtesy of MAZDA MOTORS CORP.
4. On automatic transmission models only, connect ammeter to air control valve solenoid. Current should flow to solenoid when engine speed is under 3400 ± 200 RPM. There should be no current flow to solenoid when engine speed exceeds 3600 RPM.
5. Connect No. 1 thermosensor connector and vacuum switch. With idle switch coupler removed, connect an ammeter to coasting valve solenoid. At idle speed there should be current flow. When engine speed is brought to 2000-3000 RPM and lowered from that point, current should begin to flow at about 1200 RPM (Man. Trans.) or 1400 RPM (Auto. Trans.). Reconnect idle switch coupler as before.