my 89 sentra has a problem with the ign wiring it wont shut the car off

everything works when i turn the key off and no all i unhook is the positive cable and it shuts down

Strange, the alternator usually keeps the engine running even with the battery unhooked! Sounds like the ignition switch is not turning off. When you hook the battery back up is everything turned back on inside the car with the key off? Need to know that next, if you want more info!

im sorry everything does go off when i turn the key off an the car will stay running as long as the key is on then i turn the key off and thats when i have to disconnect the battery no nothing comes on until i hook up the cable and turn the key on if i knew how to install a kill switch i would do that just so i dont have to keep getting under the hood

Has anything been done or added to it at all recently, cooling fan problem etc.? Tell ya what i would do for a true test, unhook the ignition switch under the dash, white wire connector, next time to see if engine stops, if so replace the ignition switch! You can also get a new switch for about 25.00 and just hook it up and use a screwdriver to turn it to start then off to make sure that is the problem, do not have to even mount the new switch for this test!! Go to ebay and look at a picture of the switch to see what i mean. Just the electrical switch, not the lock cylinder and the switch. Not that hard to replace the actual switch if you are a little handy with a wrench! That's all i got. Let me know how you make out.