Diesel Data: Automotive Repair

Component Tests and General Diagnostics





On-vehicle Inspection

CAUTION:
- Check that the battery cables are connected to the correct terminals.
- Disconnect the battery cables when the battery is given a quick charge.
- Never disconnect the battery while the engine is running.

Check Battery Voltage
1. If 20 minutes have not passed since the engine was stopped, turn the ignition switch ON and turn on the electrical system (headlamp, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge.
2. Turn the ignition switch OFF and turn off the electrical systems.
3. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery.

Standard voltage:12.5 - 12.9 V at 20°C (68°F)

If the voltage is less than specification, charge the battery.

Check The Battery Terminals And Fuses
1. Check that the battery terminals are not loose or corroded.
2. Check the fuses for continuity.

Inspect Drive Belt
Visually check the belt for excessive wear, frayed cords etc.
If any defect has been found, replace the drive belt.

NOTE:
Cracks on the rib side of a belt are considered acceptable. If the belt has chunks missing from the ribs, it should be replaced.





Drive belt tension measurement and adjustment
Belt tension measurement
Measure the belt tension using a mechanical tension gauge or a sonic tension meter.

Belt tension
New belt:
637.4 - 735.5 N (65 - 75 kgf, 143.3 - 165.3 lbf)
Used belt:
441.3 - 539.4 N (45 - 55 kgf, 99.2 - 121.3 lbf)

CAUTION:
- If the engine has run for 5 minutes or more, the belt tension must be adjusted as a used belt.
- When installing the V-ribbed belt, all grooves on the pulley should be covered with belt ribs.
- A loose belt causes slip noise.
- Too tight belt cause bearing of alternator and water pump to damage.

Using a mechanical tension gauge (BT-33-73F, BTG-2 type)
1. While pressing the handle (A) of the gauge, insert the belt (B) between pulley and pulley (or idler) into the gap between spindle (C) and hook (D).




2. After releasing the handle (A), read a value on the dial pointed by the indicator (B).




Using a sonic tension meter (U-505/507 type)
1. Input the belt specifications into the tension meter (A).






NOTE:
Measurement of S (Span): Calculate average value after measuring the distance 3 - 4 times.








2. Locate the micro phone (B) close to the center of belt span (A) and bounce the belt by finger 2 - 3 times. Read a value on the display.

[With A/C]





[Without A/C]




If adjustment is necessary:
1. Loosen the mounting bolts (A).
2. Tighten the adjusting bolt (B) clockwise in loose tension; loosen the bolt counterclockwise in high tension.




3. Recheck tension of the belt.
4. After adjusting tension, tighten the mounting bolts.

Tightening torque
M10 bolt:
29.4 - 41.2 N.m (3.0 - 4.2 kgf.m, 21.7 - 30.4 Ib-ft)
M8 bolt:
21.6 - 32.4 N.m (2.2 - 3.3 kgf.m, 15.9 - 23.9 Ib-ft)

Visually Check Alternator Wiring And Listen For Abnormal Noises
1. Check that the wiring is in good condition.
2. Check that there is no abnormal noise from the alternator while the engine is running.

Check Discharge Warning Light Circuit
1. Warm up the engine and then turn it off.
2. Turn off all accessories.
3. Turn the ignition switch "ON". Check that the discharge warning light is lit.
4. Start the engine. Check that the light is lit.
If the light does not go off as specified, troubleshoot the discharge light circuit.