Pinpoint Test 9

Flow Chart No. 9 - Symptom - All warning indicators inoperative.

Step 1
Check cluster ground.
1. Turn ignition switch to OFF position.
2. Partially remove instrument cluster.




3. Using an ohmmeter connected to a known good ground, connect second lead to Pins 8 and 10 (B) wire of 16-pin cluster connector.
4. Measure resistance.




5. Is resistance 5 ohms or less?

Step 2
Check supply at cluster.
1. Turn ignition switch to RUN position.




2. Check voltage at Pin 4 (R/Y) of 16-pin cluster connector.




3. Is there B+ voltage?

Component Testing
SST 4908 39285 or equivalent is used to diagnose problems with the instrument cluster magnetic gauges. Testing of the magnetic gauges can be accomplished by:
1. Disconnect connector from the appropriate sender and hook onto the matching terminals on the tester.
2. Turn the vehicle ignition switch lock cylinder to ON position.
For coolant temperature, connect a 9.7-ohm resistor between the connector and ground. For oil pressure, short the connector directly to engine ground. The centerline of the pointer should fall within the band around the H mark for coolant temperature and slightly above mid-scale for oil pressure.




Fuel Gauge
With the sending unit float arm in the empty-stop position, resistance should be 15 ohms (below E). With the sending unit float arm in the full-stop position, resistance should be 160 ohms(above F). The fuel gauge should read empty at 22.5 ohms and full at 145 ohms.







Fuel Tank Sending Unit
With ohmmeter positive lead on the signal wire lead and the negative lead on ground, check the resistance values of the fuel sending unit at various positions of the float arm. An open circuit will indicate infinity on the ohmmeter and a short will indicate zero ohms.

Coolant Temperature Gauge
Connect a 74-ohm resistor between the gauge lead and ground. The centerline of the pointer should fall within the band around the C mark.
^ If the coolant temperature gauge tests within calibration, replace engine coolant temperature sensor.
^ If the coolant temperature gauge still tests out of calibration, replace the gauge.

Temperature Sender Unit
If the coolant temperature gauge is still not indicating properly, check the engine coolant level to make certain that coolant level is still at full point. Also verify that thermostat is operating and that fan belt tension is within specification.

Oil Pressure Gauge/Oil Pressure Sender
With connector attached to the oil pressure sensor and ignition switch lock cylinder on, the centerline of the pointer should fall on or below the L mark.
^ If the oil pressure gauge tests within calibration, replace oil pressure sender.
^ If the oil pressure gauge still tests out of calibration, replace the gauge.

Charge Indicator Lamp
The integral alternator regulator (IAR) has a circuit in the voltage regulator that will indicate a high battery voltage condition. With the IAR system, two conditions can cause the charge indicator lamp to come on during vehicle operation:
1. No generator output - damaged generator, voltage regulator or wiring.
2. Overvoltage correlation - shorted generator rotor, regulator or wiring. If the system is working normally, the following conditions will be present:
^ With ignition switch lock cylinder in OFF position, charge indicator (battery symbol) lamp is off.
^ With ignition switch lock cylinder in ON (engine not running), charge indicator (battery symbol) lamp is on.
^ With ignition switch lock cylinder in RUN (engine running), charge indicator (battery symbol) lamp is off, except as noted above.
If the charge indicator lamp does not come on with the ignition switch lock cylinder in the RUN position (engine not running), check the "I" circuit (ignition switch lock cylinder to regulator "I" terminal) for an open circuit or burned out charge indicator lamp. Replace the lamp, if necessary.
^ If the charge indicator lamp does not come on, disconnect the wiring connector from the voltage regulator.
^ Connect a jumper wire from the wiring connector "I" terminal to the battery negative post cable clamp.
^ Turn the speedometer to RUN (engine not running). If the indicator lamp does not light, check the indicator bulb for continuity and replace the bulb if it is burned out. If the bulb is still good, perform the voltage regulator "I" circuit tests.

Odometer Accuracy Test
To test the odometer accuracy, drive the vehicle over a measured distance of at least 16 consecutive km (10 consecutive miles). Check measured distance against odometer measured distance. Acceptable odometer measured distance is 15.4 - 16.7 km (9.6 - 10.4 miles).

Speedometer Calibration
Speedometer accuracy can be checked by timing the vehicle on a measured mile and performing the following speedometer calibration test. The Mazda Speedo Gear Supplement Chart shows the proper speedometer gears to use for various rear axle and tire size OEM combinations.




Speedometer Calibration Test
1. Time the number of seconds it takes to travel one measured mile at an indicated 30 and 60 mph.
2. Calculate the vehicle speed using the following formula:
mph = 3600 divided by seconds
3. Acceptable ranges are the following:




SPEEDOMETER DRIVEN GEAR AND DRIVE GEAR CHART