How to remove and replace the ignition lock cylinder on a 1977 chevy 3/4 ton pickup?

It would be the pickup in the bottom of the distributor.

hi blaine.
see if this link helps you out.
How the remove the horn contact on 93 chevy 3 4 ton pickup Google Search

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see this vdio

To late-You could have tried putting WD-40 in lock. Not a long term fix but generally works.

1. NON TILT WHEEL
2. Remove the steering wheel.
3. Remove the turn signal switch.
4. Unfasten the two screws that release the buzzer switch (if equipped), then remove the switch.

Fig. Fig. 2: Removing the ignition buzzer

1. Remove the retaining screw and lift the ignition lock cylinder lamp out of the way.

Fig. Fig. 3: Ignition key lamp

1. Remove the bearing housing.
2. Detach the coil spring.
3. Remove the lock plate from the shaft.

Fig. Fig. 4: Lock lever plate removal

1. Unfasten the 2 retaining screws and lift the lock lever guide plate to expose the lock cylinder release hole.
2. Insert the key and place the lock cylinder in the LOCK position. Remove the key.
3. Insert a thin punch into the lock cylinder release hole and push inward to release the spring-loaded lock retainer. At the same time, pull the lock cylinder out of the column.

Fig. Fig. 5: Depress the lock plate which will expose the lock cylinder release hole

1. Remove the 3 retaining screws and lift out the ignition switch.

To install:

1. Position the ignition switch in the center detent position (OFF).
2. Place the shift lever in PARK.
3. Feed the wires down through the space between the housing and jacket. Position the switch in the housing and install the 3 retaining screws.

Fig. Fig. 6: Lock levers and spring assembly installed

1. Place the lock cylinder in the LOCK position, and press it into place in the column. It will snap into position.
2. The remainder of assembly is the reverse of disassembly.

1. Place lock cylinder in RUN position.

Do not remove the ignition key buzzer.

1. Insert a small drift pin into the turn signal housing slot. Keeping the drift pin to the right side of the slot, break the housing flash loose and depress the spring latch at the lower end of the lock cylinder. Remove the lock cylinder.

WARNING Considerable force may be necessary to break this casting flash, but be careful not to damage any other parts. When ordering a new lock cylinder, specify a cylinder assembly. This will save assembling the cylinder, washer, sleeve and adapter.

Ignition Switch Removal & Installation To Remove:

1. Remove the steering column trim covers.
2. Remove the wire harness from the retainers as needed.
3. Slide the 2 connectors of the multifunction switch assembly out from the bulk head connector.
4. Detach the key alarm connector from the lock assembly.
5. Remove the ignition switch mounting screws and the ignition switch from the steering column.

Ignition switch removal/installation

To Install:

1. Install the ignition switch on the lock module.
   • Tighten the screws to 42 lb in (4.7 Nm).
2. Install the key alarm connector on the lock module.
3. Slide the turn signal and multifunction switch connectors into the bulkhead connector.
4. Install the harness in the original retainers.
5. Install the steering column trim covers.

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Ignition Lock Cylinder Removal & Installation To Remove:

1. Disconnect the negative cable from the battery.
2. Disable the supplemental inflatable restraint (SIR) system.
3. Remove the steering column trim covers.
4. Turn the ignition lock cylinder to the run position.
5. Using an awl with a bent tip, insert the tip into the access hole of the ignition lock cylinder.
6. Turn the lock cylinder to start and push down and hold the lock cylinder retaining pin.
7. Release the lock cylinder to the run position and withdraw the cylinder from the steering column.

Ignition lock cylinder removal

To Install:

1. Align the slot in the steering column to the tab on the lock cylinder and install the lock cylinder until it locks in place.
2. Install the steering column trim covers
3. Connect the negative cable to the battery
4. Check for correct operation

Remove the horn button, nut the pull the wheel off with a puller.Remove the lock plate retaining spring using a Lock plate press. Remove the directional switch screws (3).. Lift that switch out of the way to remove the ignition lock screww
Pull out ign Lock Cylinder

Reverse this procedure to install

FIRST OF ALL YOU NEED STEERING WHEEL PULLER.AND LOCK PLATE TOOL J - 23653. GETTING STARTED.DISCONNECT THE NEGATIVE BATTERY CABLE.REMOVE THE LOWER TRIM PANEL.REMOVE THE STEERING COLUMN RETAINING BOLTS.LOWER THE STEERING COLUMN ASSEMBLY TO GAIN ACCESS TO THE SWITCH RETAINING SCREWS.BECAREFUL DONT DAMAGE THE COLLAPSIBLE COLUMN.MAKE SURE THE SWITCH IS IN THE LOCK POSITION.IF THE LOCK CYLINDER IS OUT PULL THE SWITCH ROD UP TO THE STOP THEN GO DOWN 1 DETENT.REMOVE THE ELECTRICAL CONNECTIONS FROM THE SWITCH.REMOVE THE SWITCH RETAINING SCREWS.REMOVE THE SWITCH FROM THE COLUMN.INSTALLATION IS THE REVERSE OF THE REMOVAL PROCEDURE.BEFORE INSTALLATION MAKE SURE THE SWITCH IS IN THE LOCK POSITION.WARNING USE ORIGINAL SCREWS.IF YOU USE TOO LONG SCREWS IT WILL PREVENT THE COLUMN FROM COLLAPSING ON IMPACT. NOW IF YOU ARE REMOVING THE IGNITION LOCK CYLINDER.DISCONNECT THE NEGATIVE BATTERY CABLE.REMOVE STEERING WHEEL.USING A STEERING WHEEL PULLER AND LOCK PLATE TOOL. J-23653 REMOVE THE TURN SIGNAL SWITCH. IT IS NOT NECESSARY TO COMPLETELY REMOVE THE SWITCH FROM THE COLUMN. PULL THE SWITCH REARWARD FAR ENOUGH TO SLIP IT OVER THE END OF THE SHAFT BUT DO NOT PULL THE HARNESS OUT OF THE COLUMN.TURN THE LOCK TO RUN.REMOVE THE LOCK RETAINING SCREWS.AND REMOVE THE LOCK CYLINDER.NOTE IF THE RETAINING SCREW IS DROPPED ON REMOVAL.IT MAY FALL INTO COLUMN REQUIRING COMPLETE DISASSEMBLY OF THE COLUMN TO RETRIEVE THE SCREW.TO INSTALL. ROTATE THE KEY TO THE STOP WHILE HOLDING ONTO THE CYLINDER.PUSH THE LOCK ALL THE WAY IN.INSTALL THE SCREW TIGHTEN THE SCREW TO 40 INCH LBS FOR REGULAR COLUMNS 22 INCH LBS FOR ADJUSTABLE COLUMNS.INSTALL THE TURN SIGNAL SWITCH AND STEERING WHEEL.WARNING THIS JOB IS A SKILL LEVEL B MEANING YOU MUST HAVE BASIC KNOWLEDGE OF COMPLEX SYSTEM.DONT DO THIS JOB IF THIS IS YOUR FIRST TIME WORKING ON A VECHICLE.

This Outlines Removal Of Both LOCK CYLINDER<< Mechanical)) And The Ignition SWITCH ITSELF<< ELECTRICAL))

1. Remove steering wheel as outlined previously.
2. Remove turn signal switch as outlined in ``Turn Signal Switch, Replace'' procedure.
3. Place ignition switch in ``Run'' position, then remove lock cylinder retaining screw and lock cylinder.
4. To install, rotate lock cylinder to stop, while holding housing as shown, Fig. 6. Align cylinder key with keyway in housing, then push lock cylinder assembly into housing until fully seated.
5. Install lock cylinder retaining screw. Torque screw to 40 inch lbs. for standard columns, or 22 inch lbs. for adjustable columns.
6. Install buzzer switch, turn signal switch and steering wheel

CABALLERO, EL CAMINO, C, K, R, V & 1986---87 G MODELS
The ignition switch is mounted on top of the mast jacket inside the brake pedal support and is actuated by a rod and rack assembly.

1. Disconnect battery ground cable.
2. Disconnect and lower steering column. On some models, it may be necessary to remove the upper column mounting bracket if it hinders servicing of switch. Use extreme care when lowering steering column to prevent damage to column assembly. Only lower steering column a sufficient distance to perform ignition switch service.
3. On Caballero and El Camino, rotate ignition lock to ``Off'' unlocked position.
4. On C, K, R and V models, rotate ignition lock to ``Off'' locked position.
5. If lock cylinder has been removed, pull switch actuator rod up to stop, then pushrod down to second (Caballero or El Camino) or first (C, K, R and V models) detent as shown, Fig. 7.
6. Remove column mounted dimmer switch, if equipped, then remove switch retaining screws and switch.
7. Reverse procedure to install, noting the following:

1. Place gear shift lever in neutral.
2. Place lock cylinder and switch in positions noted in steps 3 and 4.
3. Fit actuator rod into hole in switch slider and secure switch with retaining screws, ensuring switch does not move out of detent.
4. Install and adjust dimmer switch, if equipped, as outlined in ``Column Mounted Dimmer Switch, Replace'' procedure.
5. Torque retaining screws to 35 inch lbs., then check switch operation.