'70 Ignition Switch Replacement
The '70 Mustang was similar to the '69. However, government-mandated safety and antitheft changes meant the '70 would be considerably different inside, with a one-year-only, locking steering column. The ignition lock cylinder locks the steering column when the ignition is in the "off" position. When the steering column is unlocked to start the engine, you're moving a linkage inside the steering column that operates the ignition switch, located halfway down the column. Replacement is easy. All you have to do is remove the plastic steering-column cover.
'71-'73 Ignition Switch Replacement
Ford changed the Mustang's locking steering column again in '71-'73 models, moving the ignition switch farther down the column. A long linkage ties the ignition lock cylinder with the ignition switch way down the column. Replacement is a piece of cake.
'70-'73 Lock Cylinder Removal
Lock cylinder removal for '70-'73 Mustangs is different than for '65-'69 models. The steering wheel must be removed. Once removed, press on a release pin inside the column at the lock cylinder. Turn the lock cylinder toward "ACC" and pull it out. To reinstall, turn the lock cylinder all the way to "START" and insert the cylinder.