Section 7
DIAGNOSTIC TESTS
Short to Ground:
4.Set the VOM to measure resistance. Connect the positive (+) test lead to the case housing of the BCR. Connect the negative
Figure 7-10. – Battery Charge Rectifier
RESULTS:
1.If any of the previous steps has failed, replace the Battery Charge Rectifier.
2.If the BCR tests good, go to Test 17.
TEST 17 - CHECK BATTERY CHARGE
WINDINGS / BATTERY CHARGE RESISTOR
DISCUSSION:
The Battery Charge Winding (BCW) produces AC voltage that is delivered to the Battery Charge Rectifier. The Battery Charge Winding is a center tapped winding consisting of the following Stator Leads: Wire 66, Wire 77 and Wire 55. The Battery Charge Resistor is used as a current limiting resistor.
PROCEDURE:
1.Disconnect the Stator Leads (Wire 66 and Wire 77) from the Battery Charge Rectifier. (Be sure to disconnect Stator Lead Wire 66 “Black” from Wire 66 “Blue” connector for this test). Disconnect the Stator Lead Wire 55 from the Battery Charge Resistor.
2.Set the VOM to measure resistance at the “R x 1” scale. Connect one test lead to Stator Lead Wire 66. Connect the other test lead to Stator Lead Wire 55. Normal Battery Charge Winding resistance should be measured.
3.Connect one test lead to Stator Lead Wire 77. Connect the
other test lead to Stator Lead Wire 55. Normal Battery Charge Winding resistance should be measured.
4.Connect one test lead to Stator Lead Wire 55. Connect the other test lead to Stator Leads Wire 11 & 33 at the back of CB1. “Infinity” should be measured.
5.Connect one test lead to Stator Lead Wire 55. Disconnect Stator Lead Wire 2 from the DPE circuit breaker (CB3) and connect the other test lead to Wire 2. “Infinity” should be mea- sured.
6Connect one test lead to Stator Lead Wire 55. Connect the other test lead to frame ground. “Infinity” should be measured.
7.Connect one test lead to the Battery Charge Resistor terminal that Wire 55 was removed from. Connect the other test lead to frame ground. One (1) ohm should be measured. If 1 ohm was not measured, remove Wire 0 from the Battery Charge Resistor. Connect one test lead to Wire 0 and the other test lead to frame ground. “Continuity” should be measured. Repair or replace Wire 0 if defective and retest the Battery Charge Resistor.
BATTERY CHARGE WINDING RESISTANCE *
QP55 (Model 4702/4703)
ACROSS WIRES: | OHMS |
|
55 & 66 | 0.100Ω − 0.116Ω |
|
55 & 77 | 0.100Ω − 0.116Ω |
|
BATTERY CHARGE WINDING RESISTANCE *
QP65 (Model 4704/4705)
ACROSS WIRES: | OHMS |
|
55 & 66 | 0.104Ω − 0.120Ω |
|
55 & 77 | 0.087Ω − 0.101Ω |
|
BATTERY CHARGE WINDING RESISTANCE *
QP75 (Model 4706/4707)
ACROSS WIRES: | OHMS |
|
55 & 66 | 0.092Ω − 0.107Ω |
|
55 & 77 | 0.076Ω − 0 . 0 8 8 Ω |
|
*Resistance values In ohms at 20° C. (68° F.). Actual readings may vary depending on ambient temperature. A tolerance of plus or minus 5% is allowed.
RESULTS:
1.For Steps 2 & 3, keep in mind that the resistance values are very low. Depending upon the quality of the VOM, it may read “Continuity” across these windings. Exercise good judgement with these values.
2.If Steps 2, 3, 4, 5 & 6 fail any test, replace the Stator.
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