See Figures 1 and 2
The alternator charging system is a negative ground system, consisting of an alternator, regulator, charge indicator, storage battery, fusible link and associated wiring. The integral alternator/regulator is belt driven from the engine.
The fusible link is a short length of insulated wire located between the starter relay and the alternator that is designed to burn out, thus protecting the alternator and wiring when heavy reverse current flows, such as when a booster battery is connected incorrectly or a short to ground occurs in the wiring harness. If an alternator or charging system problem is being diagnosed, always check the condition of the fusible link first.
The alternator warning light on the Aerostar can have a different meaning than with other systems. The light may indicate a high or low voltage condition. Extended vehicle idling with high electrical loads (all accessories on) could cause the warning lamp to come on. This is not meant to indicate a problem, but merely to warn the driver that there may be a battery discharge condition.
Before performing charging or starting system tests on the van, first determine exactly what type of problem you are dealing with, such as slow cranking, battery dead, ammeter light shows charge at all times or no charge, alternator warning light does not come on or never goes out, etc.. This information will aid in isolating the part of the system causing the problem. Next, the system should be visually inspected as follows:
- Check the fusible link located between the starter solenoid and the alternator. Replace the fusible link if burned.
- Check the battery posts and cable terminals for clean and tight connections.
- Check for clean and tight wiring connections at the alternator, regulator and engine.
- Check the alternator belt tension using belt tension gauge T63L-8620-A, or equivalent and adjust the belt tension if necessary. For more information concerning accessory drive belt tightening procedures, refer to Routine Maintenance .