Aqui un poco de info para checar el sistema de arranque:
Ford Ranger 1983-1987
STARTING SYSTEM The starting system consists of the battery, starter motor, starter relay, solenoid (on diesel models), ignition switch, neutral start switch (automatic transmission) and connecting wiring. A clutch interlock switch is used with 1985-on vehicles equipped with a manual transmission. The interlock switch requires that the clutch pedal be fully depressed before the starting circuit will operate. A Motorcraft positive engagement starter is used on all gasoline models. Diesel models use a gear reduction starter with attached solenoid. When the ignition switch is turned to START with the transmission in PARK or NEUTRAL (automatic) or the clutch pedal fully depressed (1985-on manual), it transmits current from the battery to the starter relay (Figure 1). a. With positive engagement starters, the relay sends the battery current to the starter motor where it flows through a grounded pole coil attached to the starter drive plunger lever and forces the drive into engagement with the flywheel. Figure 2 is a schematic of the positive engagement starter system. b. With gear reduction starters, the relay sends the battery current to the starter solenoid, which mechanically engages the starter with the engine flywheel. Figure 3 is a schematic of the gear reduction starter system. Starting system problems are relatively easy to find. In most cases, the trouble is a loose or dirty electrical connection.
On-vehicle Testing: Three of these procedures require a fully charged 12-volt battery (to be used as a booster) and a pair of jumper cables. Use the jumper cables as outlined in Jump Starting, Chapter Eight, following all of the precautions noted. Disconnect the Thermactor bypass valve vacuum line on gasoline engines so equipped before starting this procedure. When testing has been completed, let the engine idle for 3-4 minutes before reconnecting the vacuum line.
Slow cranking starter:
1. Connect the jumper cables. Listen to the starter cranking speed as the engine is started. If the cranking speed sounds normal, check the battery for loose or corroded connections or a low charge. Clean and tighten the connections as required. Recharge the battery if necessary.
2. If cranking speed does not sound normal, clean and tighten all starter relay connections and the battery ground on the frame and/or engine. 3. Repeat Step 1. If the cranking speed is still too slow, replace the starter.
Starter relay clicks, starter does not crank:
1. Clean and tighten all starter and starter rela. connections. Make sure the terminal eyelets are securely fastened to the wire strands and are not corroded.
2. Remove the battery terminal clamps. Clean the clamps and battery posts. Reinstall the clamps and tighteri securely.
3. lfthe starter does not crank, connect the jumper cables. If the starter still does not crank, replace it.
Starter relay chatters (no click), starter does not crank:
1. Check the red/blue wire connection at the starter relay. Clean and tighten if necessary.
2. Check the relay mounting screws for a good, tight ground.
3. Place the transmission in PARK (automatic) or NEUTRAL (manual).
4. Disconnect the red/blue wire at the starter relay. Connect a jumper wire between this relay connector and the positive battery terminal.
5. Connect the jumper cables. Try starting the engine (depress the clutch on manual transmission vehicles with a clutch interlock switch).
6. If the engine starts, check the ignition switch, .eutral start or clutch interlock switch and system wiring for an open circuit or a loose connection. If the engine does not start, replace the starter relay.
Starter spins but does not crank
1. Remove the starter. See Chapter Eight.
2. Check the starter pinion gear. If the teeth are chipped or worn, inspect the flywheel ring gear for the same problem. Replace the starter and/or ring gear as required.
3. If the pinion gear is in good condition, disassemble the starter and check the armature shaft for corrosion. See Brush Replacement, Chapter Eight for disassembly procedure.
4. If there is no corrosion, the starter drive assembly is slipping. Replace the starter with a new or rebuilt unit