There are 4 different types of alternators found on the years and model ranges covered in this information:
This unit utilizes a separate, external electronic regulator. The regulator is non-adjustable. The rear terminal alternator was standard equipment on 1987 trucks, and can be found on some 1992 motor home chassis models equipped with the 7.3L diesel or 7.5L gasoline engine.
This unit was optional on 1987, standard on all 1988-92 models and standard on 1993-96 models equipped with the 4.9L and 7.5L engines. The regulator in integrated within the alternator body and is not adjustable.
This alternator is standard equipment on all 1993-96 models equipped with 5.0L, 5.8L gasoline engines and 7.3L diesel engines (except the 1996 F-Super Duty models).
This unit is optional equipment on some 1989-94 trucks and ambulance packages. A separate, electronic, fully adjustable regulator is employed in this system.
This unit is found on 1996 F-Super Duty models equipped with the 7.3L diesel engine. The regulator is integral and the fan is external.
When performing charging system tests, turn off all lights and electrical components. Place the transmission in P (AT) or N (MT) and apply the parking brake.
To ensure accurate meter indications, the battery terminal posts and battery cable clamps must be clean and tight.
See Figures 1, 2, 3 and 4
Fig. Fig. 1: Disengage all wiring harness connections from the alternator
Fig. Fig. 2: Once it is unbolted, maneuver the alternator from the engine compartment
Fig. Fig. 3: Side terminal alternator
Fig. Fig. 4: Rear terminal alternator
Some engines are equipped with a ribbed, K-section belt and automatic tensioner. A suitable tool must be made to remove the tension from the tensioner arm. Loosen the idler pulley pivot and adjuster bolts before using the tool..