ignition security system

[fmwong]

97 lumina with resister in key.
security light comes on once in awhile while driving and goes away
once in awhile will not crank, no clicking or anything, just dash lights and fuel pump power. then starts fine.
load check of starter shows low draw
check and switched keys thinking it might had a bad resistor

suspect ignition security feature. can not make happen on demand. no information on security system in repair manuals. any ideas or diagrams?

thanks

[Supergumby]

From another thread.......


There are two contacts in the ignition cylinder that touch the black pellet on the key to read the resistance of the pellet. These contacts are connected to a two-wire harness that runs outside of the ignition cylinder, and they twist back and forth every time the car is started and shut off.

If the resistance of the pellet is not read correctly when the key is rotated to the ignition ON position, the security system (PASSKEY) will disable the starter and fuel system for approximately four minutes.

After years of this twisting back and forth, the wire strands will crack and break inside the insulation, becoming more and more intermittant, and finally breaking off of the cylinder completely.

Sounds like yours are becoming intermittant. Drop the closeout panel below the steering column, and look for a small bright orange cable. disconnect this cable at the small two-way connector near the high-beam switch. Using a DVOM, measure the resistance between the terminals of the connector on the orange cable with the key inserted. The actual resistance is not as important for this test as continuity/open circuit. Now rotate the key through all the positions, and watch for the meter to read open. If it does, you need a new key cylinder (and new keys - the new cylinder will have a different cut, and you'll need keys with your car's proper resistance value cut to the new cylinder).

Good Luck.