86 Alternator Regulator

ALTERNATOR & REGULATOR - NIPPONDENSOArticle Text

1986 Toyota MR2For RSe 7 HotRod Lane C'Ville VA 22901

Copyright © 1997 Mitchell InternationalSunday, May 19, 2002 11:49PM

ARTICLE BEGINNING

1986 Alternators & Regulators NIPPONDENSO ALTERNATORS

Toyota: Camry, Celica, Corolla, Cressida, Land Cruiser, MR2, Pickup, Supra, Tercel, Van, 4 Runner

DESCRIPTION

Nippondenso alternators are conventional 3-phase alternatorsutilizing 3 positive and 3 negative diodes to rectify current.Charging system voltage is controlled by an internal IntegratedCircuit (IC) voltage regulator, or external voltage regulators. SomeToyota models use engine, ignition, and charging light relays.

NIPPONDENSO ALTERNATOR APPLICATION TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄModel Amps. (1) Part No.

Toyota Camry Diesel .............. 55 .............. 27020-64080 Gas ................. 55 .............. 27020-63020 Celica ............... 55 .............. 27060-35060 Corolla (FWD) ........ 55 .............. 27060-16030 Corolla (RWD) Carb. ............... 55 .............. 27060-63030 Fuel Inj. ........... 55 .............. 27060-16030 Cressida ............. 65 .............. 27060-43060 Land Cruiser ......... 55 .............. 27020-35060 MR2 .................. 60 .............. 27060-16050 Pickup ............... 55 .............. 27020-35060 Supra ................ 65 .............. 27060-43060 Tercel ............... 50 .............. 27020-15120 Van .................. 60 .............. 27060-72060 4Runner .............. 55 .............. 27060-35060

(1) - Vehicle manufacturer's part number.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

TESTING

ON-VEHICLE

Preliminary Inspection Check alternator wire harness connections and drive belt

ALTERNATOR & REGULATOR - NIPPONDENSO

tension. Check "ENGINE", "CHARGE", "IGN" and alternator fusible linkfor continuity. Battery must be fully charged prior to beginning test.

No Load Test 1) Connect battery/alternator tester according tomanufacturer's instructions. Check amperage and voltage with enginerunning at 2000 RPM. On all models, alternator output should be lessthan 10 amps. 2) Voltage should be 13.8-14.8 volts on Camry Diesel,Corolla, and Tercel (without IC regulator). Voltage reading on allother models should be 13.5-15.1 volts. 3) If voltage reading is above specified range, replace ICregulator. If voltage reading is less than specified, ground "F" (fullfield) terminal. See Fig. 3. 4) If voltage now climbs above specified range, replace ICregulator. If reading remains below specified range, repair or replacealternator.

Fig. 1: Toyota Alternator Output Test

Load Test Start engine. Turn on high beam headlights and place heatercontrol on "HI". Run engine at 2000 RPM and check amperage. Ammetershould read more than 30 amps. If reading is less, repair or replacealternator.

NOTE: If reading is low due to a fully charged battery, it may be necessary to crank engine with coil disconnected for about 15 seconds to partially discharge battery.

CONTROL RELAYS

Charging Light Relay (Camry Diesel, RWD Corolla) 1) Connect ohmmeter positive lead to terminal No. 2 andohmmeter negative lead to terminal No. 1 on charging light relaylocated under hood. Ohmmeter should indicate continuity. See Fig. 4. 2) Reverse ohmmeter leads. Ohmmeter should now indicate nocontinuity. Ensure there is no continuity between terminals No. 3 and


4. If relay does not test as indicated, replace relay. 3) Connect positive side of battery to terminal No. 1.Connect negative side of battery to terminal No. 2. Check forcontinuity between terminals No. 3 and 4. If relay does not test asindicated, replace relay.

Fig. 2: Testing Toyota Charging Light Relay

Engine Main Relay (Camry, Corolla & MR2) 1) Using an ohmmeter, check for continuity between terminalsNo. 1 and 3, and between terminals No. 2 and 4. on engine main relaylocated under hood. See Fig. 5. Ensure there is no continuity betweenterminals No. 4 and 5. If relay does not test as indicated, replace. 2) Apply battery voltage across terminals No. 1 and 3. Usingan ohmmeter, check for continuity between terminals No. 4 and 5.Ensure there is no continuity between terminals No. 2 and 4. If relaydoes not test as indicated, replace.

ALTERNATOR & REGULATOR - NIPPONDENSOArticle Text (p. 4)1986 Toyota MR2For RSe 7 HotRod Lane C'Ville VA 22901

Fig. 3: Testing Toyota Engine Main Relay

Ignition Relay (Tercel & Van) 1) Using an ohmmeter, check for continuity between terminalsNo. 1 and 3. on ignition relay located under hood. Check that there isno continuity between terminals No. 2 and 4. See Fig. 6. If relay doesnot test as indicated, replace relay. 2) Apply battery voltage across terminals No. 1 and 3. Usingan ohmmeter, check for continuity between terminals No. 2 and 4. Checkfor no continuity between terminals No. 3 and 5. If relay does nottest as indicated, replace.

Fig. 4: Testing Toyota Ignition RelayTercel ignition relay is square and Van relay is round.


OVERHAUL

DISASSEMBLY

Toyota Diesel Engine Equipped Models 1) Remove vacuum pump and "O" ring (if equipped). Removenuts, insulator, rubber washer, and cover. See Fig. 7. Remove screw tobrush holder and disconnect Blue wire. Pull out brush holder with ICregulator. Remove screw and disconnect White wire. 2) Remove screws and separate IC regulator from brush holder.Remove 3 through bolts. Pull drive housing and rotor away from stator.Remove pulley nut, washer, pulley, fan and spacer. Press rotor out ofdrive housing. Remove bearing retainer and front bearing. 3) Remove 2 rubber caps, 4 nuts, condenser, and 2 insulators.Remove rectifier and stator from end housing. Remove 4 insulators fromrectifier studs. Unsolder stator leads from rectifier.

Fig. 5: Testing IC Voltage Regulator

Corolla, Prelude & Tercel (Without IC Regulator)


1) Remove 3 alternator through bolts. Pull drive housing androtor away from stator. Remove pulley nut, washer, pulley, fan andspacer. Press rotor out of drive housing. Remove bearing retainerscrews and front bearing. 2) Remove condenser, clip and terminal insulators from endhousing. Remove stator/rectifier assembly from end housing. Removeinsulators from rectifier studs. Unsolder stator leads from rectifier.On Corolla alternator, unsolder IC regulator leads from rectifier.

Fig. 6: Exploded View of Camry AlternatorFWD Corolla and Pickup alternators are similar.

All Other Models 1) Remove nut and terminal insulator. Remove nuts and endcover. Remove 4 stator lead screws from rectifier assembly. Removebrush holder, IC regulator, rectifier assembly, and insulators. 2) Remove 4 nuts and end housing. Remove pulley nut (ifequipped) and pulley. Remove stator through bolts and stator. Pressrotor out of drive housing. Remove bearing retainer and front bearing.

BENCH TESTING

NOTE: Also see CHARGING SYSTEM TROUBLE SHOOTING in the TROUBLE SHOOTING - BASIC PROCEDURES article.

Rotor


1) Check rotor for open field windings by using an ohmmeteracross slip rings. Rotor resistance should be 4.0-4.2 ohms for Tercelalternator without IC regulator and 2.8-3.0 ohms for all other models. 2) Check rotor for shorts to ground by connecting ohmmeterbetween slip ring and rotor shaft. Ohmmeter should show no continuity.Check slip rings for wear or pitting. Turn rotor on lathe ifnecessary. Check bearing and replace if necessary.

Stator Connect ohmmeter between 2 stator leads. Ensure there iscontinuity between all stator leads. Connect ohmmeter between eachstator lead and metal core. Ohmmeter should show no continuity. Ifcontinuity is indicated, stator must be replaced.

Rectifier Diodes 1) With rectifier assembly on bench, contact diode plate withone probe and each of the 3 diode leads with other probe. Noteohmmeter reading. Reverse probes and repeat test. Check all diodes inthis manner. 2) All diodes should show a low reading in one direction andNO reading in opposite direction. If any rectifier diode is defective,replace rectifier assembly. 3) On all models, set ohmmeter to x100 ohm scale. Check forcontinuity between terminals "B" and "F". There should be continuityin one direction only.

Fig. 7: Exploded View of Spectrum & Sprint AlternatorsToyota alternators are similar.

ALTERNATOR & REGULATOR - NIPPONDENSOArticle Text (p. 8)

COMPONENT REPLACEMENT

Brushes 1) Check for cracks and minimum length of .18-.22" (4.5-5.5mm). If damaged or worn, replace brushes. Brushes should slidesmoothly in holders. Install new springs when replacing brushes.Solder brush wire. 2) New brush protrusion should be .49" (12.5 mm) for Tercel,.79" (20. mm) for diesel engine equipped models, .41" (10.5 mm) forall other models.

REASSEMBLY

1) To assemble, reverse disassembly procedure. Press brushesinto holder against spring tension. To prevent brushes from falling,insert a wire through hole in rectifier, end housing and brush holder. 2) Press rear bearing onto rotor shaft. Pack drive endbearing with grease, and install. Install felt ring, cover, andbearing retainer (if equipped). Tighten body screws and remove brushretaining wire. Ensure stator terminal insulators are in place,otherwise alternator may short to ground.

END OF ARTICLE

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86 Alternator Regulator