ALTERNATOR7 AmpFig. 194 - Testing StatorTesting RectifierAttached to the blower housing baffle are two small blackboxes; one (the rectifier box) has two black leads, andthe other (the regulator box) has one red lead and onewhite lead. These leads connect to four pins in thedetachable plug. Leave boxes installed on blowerhousing. Test rectifier with multimeter (using resistancescale) to check resistance from each black lead pin toblower housing (in an unpainted clean area). See Figure195. After checking each pin, reverse meter leads andrecheck. The meter should show a reading in onedirection only. If either of the rectifier pins shows a meterreading both ways, the rectifier is defective. If either ofthe pins shows no reading either way, the rectifier isagain defective. Remove rectifier lead pins fromdetachable plug and replace rectifier box. Instructionsheet packed with rectifier assembly shows how toremove lead pins from detachable plug.Fig. 195 - Testing RectifierTesting RegulatorTest regulator with multimeter (using resistance scale)as described in “Testing Rectifier, “ except touching redlead pin and white lead pin, as shown in Figure 196. Ifthe red lead pin shows a reading in either direction, theregulator is defective. The white lead pin must show aweak reading in one direction only. If meter indicatesotherwise, regulator is defective. Replace regulator byremoving rectifier pins from plug and installing rectifierpins in new plug furnished with new regulator.Instruction sheet packed with regulator assembly showshow to replace pins in plug.Fig. 196 - Testing RegulatorTesting Alternator OutputInstall ammeter in series with charging lead, as in Figure197. Start engine. Ammeter should indicate charge. Ifbattery is fully charged, ammeter will show little or noneedle deflection. If such is the case, connect a 12 voltheadlight lamp across battery terminals to apply a load.Ammeter should then show increased charge rate.If ammeter shows no charge, and if rectifier andregulator have been tested, look for loose connections,broken or frayed wires, etc. If there is no visible fault,replace stator and re-test alternator output.60
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