Prelude L4-2056cc DOHC (1990)
Fig. 9 Alternator Full Field Access Hole Location. Nippon Denso Units
b. Remove protective cover from alternator end cover. Perform full field test by inserting a suitable tool into full field access hole located on end
cover, Figs. 8 & 9. When alternator is in full field, system voltage will rise quickly. Do not allow voltage to exceed 18 volts or damage to
electrical system may result. Note tester amperage readings with alternator in full field. If readings are now within specification, replace
voltage regulator. If readings are still not within specification, replace alternator.