Cold Dr-5 - Choke Plate Position With Engine Running Check

Remove air cleaner lid. Set choke. Start engine and observe choke plate position. Choke plate should open part way. If choke plate is not opening properly, check vacuum supply to choke vacuum kick. If choke plate opened properly, connect a voltmeter between the choke heater wire at choke control switch and ground.
If air temperature is less than 55°F (13°C), voltage reading should be 5-9 volts. If air temperature is greater than 80°F (27°C), voltage reading should be within one volt of battery voltage. If voltage is not within specification, go to step 5). On 2-Bbl. models, if voltage reading is within specifications, turn ignition off. Disconnect wire from choke control that goes to electric choke heater.

Fig 1: Measuring Choke Control Switch Voltage
Connect an ohmmeter between choke heater wire and choke heating element retaining screw. Reading should be 4-12 ohms. If resistance is not within specification, replace choke heating element. If resistance is okay, proceed to COLD DR-6 .

Fig 2: Measuring Choke Heater Wire Resistance
On 4-Bbl. models, if voltage reading is okay, connect voltmeter to choke heating element harness connector and ground. There should be voltage present. If there is voltage at heater, proceed to COLD DR-6 . If voltage reading is not okay, repair choke control switch wiring for an open circuit.

Fig 3: Checking Heating Element Harness Connector for Voltage
If voltage reading in step 2) was not as specified, connect voltmeter to choke control switch ignition feed wire and ground. Voltage reading should be within one volt of battery voltage. If voltage reading is okay, replace choke control switch.

Fig 4: Checking For Voltage to Choke Control Switch
If voltage is not within specification, turn ignition off. Disconnect oil pressure switch connector. Connect voltmeter to engine harness connector at oil pressure switch terminal "C" and ground. Turn ignition switch to the "RUN" position. Voltage should be within one volt of battery voltage.

Fig 5: Measuring Voltage at Oil Pressure Switch Connector
If voltage is not within specification, repair harness to ignition switch for an open circuit. If voltage is within specification, turn ignition off. Disconnect ignition feed wire from choke control switch. Connect an ohmmeter between engine harness connector at the oil pressure switch terminal "A" and choke control switch wire.

Fig 6: Checking for Continuity Between Oil Pressure Switch Connector & Choke Control Switch
Ohmmeter should show continuity. If there is continuity, replace oil pressure switch. If no continuity, repair harness for an open circuit.