1989 Ford F-150 ignition problem

Sounds like the starter has gone again? Could have just got stuck try tapping it a few times with hammer then try and start vehicle. If this doesn't work. Easiest way to check. Is to take it off vehicle and bench test it.

The starter solonoid is still trying to start the car. This could be because its was stuck. Now I suspect it has burnt out. The cause of this could be a bad connection at starter wires or a faulty ignition switch.

TESTING (ON-VEHICLE)
CAUTION:Ensure transmission is in Park on A/T models or Neutral on M/T models prior to testing starter.

STARTER RELAY TEST
If vehicle will not start and battery is fully charged, remove Red/Blue wire connector from starter relay. Ensure connection is clean and secure and relay bracket is securely grounded.
If starter still will not operate, connect jumper wire between Red/Blue wire connector of starter relay and positive battery terminal. Ensure transmission is in Park on A/T models or Neutral on M/T models.
If relay operates, check ignition, neutral safety or clutch switch operation and wiring circuits. Replace relay if it failed to operate with jumper wire.
LOAD TEST
Connect starter load tester on battery terminals. Ensure no current is flowing through the ammeter and carbon pile of tester. Disconnect terminal "S" of starter relay.
Connect remote starter switch between terminal "S" and positive battery terminal. Ensure transmission is in Park on A/T models or Neutral on M/T models prior to testing starter.
Crank engine with ignition off and note voltmeter reading. Stop cranking engine. Turn tester carbon pile to achieve voltage obtained while cranking. Note ammeter reading. Replace or repair starter if current exceeds specification. See STARTER SPECIFICATIONS table.
Fig. 1: Starter Load Test Connections
TESTING (OFF-VEHICLE)
NO-LOAD TEST
Connect battery, jumper cables and starter tester to starter. See Fig. 1. Ensure no current is flowing through the ammeter and carbon pile of tester.
Operate starter and note voltmeter reading. Disconnect battery from starter. Turn carbon pile to achieve voltage obtained while starter was operating. Note ammeter reading. Replace or repair starter if current exceeds specification. See STARTER SPECIFICATIONS table.
ARMATURE OPEN CIRCUIT TEST
An open armature circuit can be detected by inspecting the commutator for evidence of burning. If burning is present, replace armature assembly. Check for damage to other related components.
ARMATURE & FIELD GROUNDED CIRCUIT TEST
Connect voltmeter and battery terminals to components. See Fig. 2. If voltmeter shows any voltage, windings are grounded.
Fig. 2: Armature & Field Grounded Circuit Tests
REMOVAL & INSTALLATION
Disconnect battery ground cable. Raise vehicle. Disconnect relay to starter cable at starter. Remove starter mounting bolts and ground cable. Remove starter from vehicle. To install, reverse removal procedure. Tighten bolts or nuts to specifications.
OVERHAUL
During disassembly, note location of brush holder with respect to end terminal. On field coil which operates drive gear actuating lever, bend edges on field coil retaining sleeve and remove sleeve and retainers. Cut positive brush leads from field coils as close to field connection point as possible.
During reassembly, replace brushes using a 300-watt soldering iron and rosin core solder. Lubricate armature shaft splines with Lubriplate. Fill drive end housing bearing bore with Grease (ESB-M1C63-A) approximately 1/4 full. Tighten through bolts to 55 INCH lbs. (6-2 N.M).

Starter Drive Will Not Disengage

Starter motor loose on mountings. Tighten starter attach bolts

Worn drive end bushing. See STARTER article

Damaged engine flywheel teeth. Replace flywheel and starter pinion gear for damage

Drive yolk return spring broken or missing. Replace return spring

Faulty ignition switch. Replace ignition switch

Insufficient clearance between winding leads to solenoid terminal and main contact in solenoid. Replace starter solenoid

Starter clutch not disengaging. Replace starter clutch

Ignition starter switch contacts sticking. Replace ignition switch

Starter Relay Operates but Solenoid Does Not
Faulty solenoid switch, switch connections or relay. Check all wiring between relay and solenoid or replace relay or solenoid as necessary

Broken lead or loose soldered connections. Repair wire or wire connections as necessary

Solenoid Plunger Vibrates When Switch is Engaged
. Weak batteryCharge or replace battery as necessary

Solenoid contacts corroded. Clean contacts or replace solenoid
Faulty wiring. Check all wiring leading to solenoid

Broken connections inside switch cover. Repair connections or replace solenoid
Open hold-in wire solenoid.
Low Current Draw

Worn brushes or weak brush springs. Replace brushes or brush springs as necessary

High Pitched Whine During Cranking Before Engine Fires but Engine Fires and Cranks Normally

Distance too great between starter pinion and flywheel. Align starter or check that correct starter and flywheel are being used

High Pitched Whine After Engine Fires With Key released. Engine Fires and Cranks Normally.
Distance too small between starter pinion and flywheel. Flywheel runout contributes to the intermittent nature

The relay (solonoid) is stuck. That is the problem. When you said you "replaced it" did you replace it with a new one or just replace it back? If not new, when you took it off, it freed it off. You will probably be able to do this again. But it's not going to get any better. Try tapping the solonoid. This could free it again. If you replaced it with new something must be wired wrong or loose? Check earth wire on right side of engine block. Also the solonoid is earth/grounded through it's mounting bolt's.

Starter Cranks Engine Slowly

if battery is fully charged and we have a new solonoid we need to check connections again. Or replace the starter motor itself. You said you tested it. And it was ok. Perhaps the armature is bent or bearings worn. It's definately on the starter or solonoid. The vehicle has not overheated? We have a good oil viscosity? You could first try jump starting off another vehicle to get good battery voltage see what happens then. It could just be the battery?

Battery weak or defective. Charge or replace battery as necessary
Engine overheated. See ENGINE COOLING SYSTEM article
Engine oil too heavy. Check that proper viscosity oil is used
Poor battery-to-starter connections. Check that all between battery and starter are clean and tight
Current draw too low or too high. See Bench Tests in STARTER article
Bent armature, loose pole shoes screws or worn bearing. See STARTER article
Burned solenoid contacts. Replace solenoid
Faulty starter. Replace starter