Mazda MX-5 NA silhouetteMX-5 NA

CHARGING SYSTEM - Brush Spring / Rectifier / Drive Belt

G-15prose procedure

Drive-belt deflection table applies to P/S- or P/S + A/C-equipped vehicles.

Continued from G-14

Brush Spring

  1. 1
    Measure the force of the brush spring with a spring pressure gauge.
    Read the spring pressure gauge at a brush tip projection of 2mm (0.079 in).
    Hand using a spring pressure gauge to measure brush spring force. A 2mm (0.079 in) brush tip projection dimension is called out.
    05U0GX-032
  2. 2
    Replace the spring if necessary.
Brush spring standard force
3.1—4.3 N (320—440 g, 11.3—15.5 oz)N
Brush spring minimum force
1.6—2.4 N (160—240 g, 5.6—8.5 oz)N

Rectifier

Rectifier Inspection

  1. 1
    Check for continuity of the diodes with an ohmmeter.
    Rectifier internal circuit showing the three stator-phase inputs P1, P2, P3 with six diodes connecting to positive terminal B and ground rails E and T.
    05U0GX-033
  2. 2
    Replace the rectifier if necessary.

Rectifier diode continuity check

E
Positive (Red)P1, P2, P3
ContinuityYes
B
Positive (Red)P1, P2, P3
ContinuityNo
T
Positive (Red)P1, P2, P3
ContinuityNo
P1, P2, P3
Positive (Red)E
ContinuityNo
P1, P2, P3
Positive (Red)B
ContinuityYes
P1, P2, P3
Positive (Red)T
ContinuityYes

DRIVE BELT

Inspection

Drive Belt Inspection

  1. 1
    Remove the air intake pipe.
  2. 2
    Check the drive belts for wear, cracks, or fraying. Replace if necessary.
  3. 3
    Verify that the drive belts are correctly mounted on the pulleys.
    Drive belt cross-section comparison: V BELT profile at top; V RIBBED BELT shown in three views — correct seating (O), misaligned/incorrect mounting (X) — illustrating proper ribbed-belt alignment in the pulley groove.
    05U0BX-009
  4. 4
    Check the drive belt deflection by applying moderate pressure (98 N, 10 kg, 22 lb) midway between the pulleys as shown in the figure. Adjust if necessary.
    Drive-belt routing diagram for P/S or P/S + A/C equipped car: pulley layout showing ALTERNATOR, P/S, A/C, and CRANKSHAFT pulleys with arrows indicating belt deflection measurement points between pulleys.
    05U0BX-010

Drive belt deflection mm (in)

Alternator
New8.0—9.0 (0.31—0.35)
Used9.0—10.0 (0.35—0.39)
P/S, P/S + A/C
New8.0—9.0 (0.31—0.35)
Used9.0—10.0 (0.35—0.39)
A/C
New8.0—9.0 (0.31—0.35)
Used9.0—10.0 (0.35—0.39)
Support our work!

Search Manual

Search pages, specs, and procedures