How do i remove ignition switch from 1975 plymouth duster

To replace the ignition tumbler in a 1975 Dodge Sportsman RV, you will need to follow these steps:

1. Remove the steering column cover: Start by removing the screws or bolts that hold the steering column cover in place. Once the cover is removed, you should be able to access the ignition switch and tumbler.
2. Disconnect the electrical connections: There should be two electrical connections that attach to the ignition switch. Disconnect these before attempting to remove the tumbler.
3. Remove the retaining screw: Use a screwdriver to remove the retaining screw that holds the tumbler in place.
4. Remove the tumbler: After removing the screw, the tumbler should slide out of the ignition switch.
5. Install the new tumbler: Insert the new tumbler into the ignition switch, making sure it is securely in place.
6. Reinstall the retaining screw: Use the screwdriver to reinstall the retaining screw.
7. Reconnect the electrical connections: Reconnect the two electrical connections that you disconnected in step 2.
8. Replace the steering column cover: Once everything is back in place, replace the steering column cover and secure it with the screws or bolts.
9. Test the new tumbler: Finally, test the new tumbler to make sure it is working properly and that the RV starts and runs smoothly.

Probably need to check your neutral safety switch adjustment

Yes that is the classic symptom of a defective ignition switch. They were recalled for this years 18 years ago. I am a retired Ford dealer tech.

A place on the web for such info is at For A Bodies Only. Here is a link.
Electrical and Ignition

not starter or alternator do you have any codes? if you have an electronic odometer ,put key in ignition and turn it on and off 3 times without starting engine, and stop with ignition in the on possion and you will get codes where millage is displayed ,at the end of codes it will say DONE

You have to adjust the shifter cable at the switch the two are linked together.

Sounds like your shifter is out of adjustment. If is not fully in park the key is locked into the ignition switch and the switch stays on.

FIRST OF ALL, TURN OFF RADIO,DISCONNECT NEGATIVE BATTERY CABLE. IF EQUIPPED WITH TILT STEERING COLUMN,REMOVE TILT LEVER.CAREFULLY REMOVE THE UPPER AND LOWER STEERING COLUMN COVERS. REMOVE THE 3 TAMPER PROOF TORX IGNITION SWITCH MOUNTING SCREWS USING SNAP ON TOOL TTXR15A2 OR EQUIVALENT. GENTLY PULL THE SWITCH AWAY FROM THE COLUMN AND REMOVE THE 2 ELECTRICAL CONNECTORS FROM THE IGNITION SWITCH. WITH THE KEY IN THE LOCK POSITION, DEPRESS THE KEY CYLINDER RETAINING PIN FLUSH WITH THE KEY CYLINDER SURFACE. ROTATE THE KEY CLOCKWISE TO THE OFF POSITION THE KEY CYLINDER SHOULD NOW BE UNSEATED. ROTATE THE KEY CYLINDER COUNTER CLOCKWISE BACK TO THE LOCK POSITION, AND REMOVE THE LOCK CYLINDER. ( TO INSTALL ) CONNECT THE ELECTRICAL CONNECTORS TO THE IGNITION SWITCH. BE SURE THE CONNECTORS ARE SECURELY LOCKED IN PLACE. MOUNT THE IGNITION SWITCH TO THE COLUMN 3 SCREWS FOR VECHICLES WITH THE TILT STEERING COLUMN THE SHIFTER MUST BE IN THE PARK POSITION AND THE PARK LOCK DOWEL PIN AND THE COLUMN LOCK FLAG MUST BE INDEXED BEFORE THE SWITCH IS INSTALLED. PLACE SHIFTER IN THE PARK POSITION. PLACE THE IGNITION SWITCH IN THE LOCK POSITION. THE SWITCH IS IN THE LOCK POSITION WHEN THE STEERING COLUMN LOCK FLAG IS PARALLEL TO THE IGNITION SWITCH TERMINALS. POSITION THE PARK LOCK DOWEL PIN OF THE IGNITION SWITCH SO IT ENGAGES THE STEERING COLUMN PARK LOCK SLIDER LINKAGE. APPLY A LIGHT COATING OF GREASE TO THE PARK LOCK DOWEL PIN AND THE COLUMN LOCK FLAG. POSITION THE IGNITION SWITCH AGAINST THE LOCK HOUSING OPENING ON THE STEERING COLUMN. BE SURE THE SWITCH PARK LOCK DOWEL PIN ENTERS THE SLOT IN THE PARK LOCK SLIDER LINKAGE INSTALL THE RETAINING SCREW AND BRACKET. TORQUE THE SCREW TO 26 INCH LBS. INSTALL THE STEERING COLUMN COVERS AND THE TILT LEVER IF REMOVED. WITH THE KEY CYLINDER AND THE IGNITION IN THE LOCK POSITION INSTALL THE KEY CYLINDER INTO THE SWITCH UNTIL IT BOTTOMS. RECONNECT THE NEGATIVE BATTERY CABLE AND THE CHECK THE IGNITION SWITCH FOR PROPER OPERATION OF HALO LIGHT SHIFT LOCK IF EQUIPPED AND COLUMN LOCK.ALSO CHECK FOR PROPER OPERATION OF THE IGNITION SWITCH ACCESSORY, LOCK OFF, RUN AND START FUNCTIONS.

Check power distribution panel near battery for blown fuses.

If the key won't start it; it might not be the key ignition, but rather; the ignition that has a stem that goes from the key ignition down on the steering colunm. However, you can get key ignitions for them, or buy the whole steering colum then take the key ignition out of it. But, I would suggest more information is needed before I can conclude that it is just the key ignition. Hope this help~!