I have a 1994 olds. bravda 4.3, when vehicle is in the off and parked position with the key out of the ignition, the heater fan motor continues to run even with the fan switch in the off position, to stop the fan from running till i have a fix i've pulled off the purple wire going to the fan under the hood, I have replaced the following to try and fix the problem: i replaced and installed a brand new 3 speed switch and a main console dash light switch, and also a new fan motor, the single purple wire from the fan motor goes to a wire block that my local GM dealer says is a "AC heater wiring extensions" part number 12154023, the wire block has 4 wires going through it and one of those wires are my purple fan motor wire, the 4 wires then go to a relay with a resistor built in and grounded to the engine compartment fire wall,the wires have gotten hot enough at some time that the wires have melted to a certain degree, i can't find that part of the wire harness to replace the extension, please contact me if you have access to or if you can direct me to this AC heater wiring extension.

Do you know how to do electrical testing ?
PINPOINT TEST E: WINDSHIELD WIPERS WILL NOT PARK AT PROPER POSITION E1 CHECK WIPER MOTOR GROUND

• Disconnect connector from windshield wiper motor.
• Check continuity to ground at Circuit 57 (BK).

Is ground OK? Yes No GO to E2 . SERVICE open in Circuit 57 (BK). RESTORE vehicle. RETEST system. E2 CHECK FOR POWER AT WIPER MOTOR

• Place ignition switch at RUN and multi-function switch at OFF.
• Check for battery voltage between Pin 1, Circuit 65 (DG) and Pin 4, Circuit 57 (BK) at the windshield wiper motor connector.

Is B+ present? Yes No GO to E3 . SERVICE open circuits. RESTORE vehicle. RETEST system. E3 CHECK MOTOR CIRCUIT CONTINUITY THROUGH WINDSHIELD WIPER CONTROL MODULE

• With multi-function switch at OFF, check continuity between Circuit 28 (BK/PK) and 56 (DB/O) and between Circuits 61 (Y/R) and 63 (R).

Is continuity OK? Yes No GO to E5 . GO to E4 . E4 CHECK CIRCUITS TO WIPER CONTROL MODULE

• Disconnect wiper control module connector.
• Check continuity of Circuits according to the chart below from the wiper motor to the wiper control module.
  
  Wiper Control Module Connector Wiper Motor Connector Pin Circuit Pin 6 Pin 2 28 (BK/PK) Pin 8 Pin 6 56 (DB/O) Pin 12 Pin 5 61 (Y/R) Pin 13 Pin 3 63 (R)

Is continuity present? Yes No REPLACE wiper control module. RESTORE vehicle. RETEST system. SERVICE open circuits. RESTORE vehicle. RETEST system. E5 CHECK WIPER MOUNTING ARM/PIVOT SHAFT

• Check that windshield wiper mounting arm and pivot shaft and linkage is not bent, cracked or mis-positioned.

Is windshield wiper mounting arm and pivot shaft linkage OK? Yes No REPLACE windshield wiper motor. RESTORE vehicle. RETEST system.

Most if not all vehicles have a Electronic Park Lock (EPL)/Ignition Lock Cylinder Control Actuator: If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an ignition lock cylinder control actuator system in the steering column. The ignition lock cylinder control actuator purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The column ignition lock system consists of an ignition lock cylinder control actuator, and a park position switch that is located in the automatic transmission shift lock control switch. The ignition lock cylinder control actuator contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column. Or it has
Linear Shift Assembly: If the vehicle is equipped with a column mounted gear shift, it has a linear shift assembly on the steering column. The linear shift assembly has a cable that runs from the linear shift assembly to the ignition lock cylinder case. The purpose of this cable is to prevent the ignition key from being turned to the OFF position when the transmission is in gear and the vehicle may still be moving. The linear shift assembly cable contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.
Your best bet is to take it to a ASE certified repair shop or the dealer ! The fix involves taking the steering column apart an or the floor shifter assembly ! Also electrical test to determine what is the problem !
Your

Your key is stuck ? It won't move , it won't come out of the lock cylinder ? Can you shift it from park to drive , neutral etc... Are there any lights lit on the dash , yellow wrench light , service vehicle soon light ? any messages on Driver Information Center ? Your Cadillac has numerous electronic features controlled by modules - computers ! If your not familiar with electronics an these things I suggest you take it to someone who is . Does you Cadillac have console fool shifter ?
Electronic Park Lock (EPL)/Ignition Lock Cylinder Control Actuator: If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an ignition lock cylinder control actuator system in the steering column. The ignition lock cylinder control actuator purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The column ignition lock system consists of an ignition lock cylinder control actuator, and a park position switch that is located in the automatic transmission shift lock control switch. The ignition lock cylinder control actuator contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.
Linear Shift Assembly: If the vehicle is equipped with a column mounted gear shift, it has a linear shift assembly on the steering column. The linear shift assembly has a cable that runs from the linear shift assembly to the ignition lock cylinder case. The purpose of this cable is to prevent the ignition key from being turned to the OFF position when the transmission is in gear and the vehicle may still be moving. The linear shift assembly cable contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.
The windows are no exception , they are controlled by modules in each door an are connected by a serial data communication bus !
The vehicle is equipped with power windows controlled by the door modules. Each passenger door window can be operated, either from a power window switch built into the driver door switch assembly (DDSA) , or, from a power window switch mounted locally on its associated door. The driver door window can be operated only from the driver door power window switch built into the DDSA.
When the driver door module (DDM) receives a driver door window switch request from the DDSA, the DDM examines the request and inspects to see if it has received any messages from any of the other vehicle modules prohibiting the movement. If no prohibitive messages have been received, the DDM then applies power and ground to the driver door window motor to move the window as requested.
When a passenger door module, passenger front door module (PDM), LH rear door module (LRDM), or RH rear door module (RRDM), receives a window switch request from, either the DDSA or the window switch mounted locally to its door, the passenger door module examines the request and inspects to see if it has received any messages from any of the other vehicle modules prohibiting the movement. If no prohibitive messages have been received, the passenger door module then applies power and ground to its associated window motor to move the window as requested.

Does it go into the lock position ? Will the shifter go into the park position ? Is it a automatic transmission ?
Electronic Park Lock (EPL)/Ignition Lock Cylinder Control Actuator: If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an ignition lock cylinder control actuator system in the steering column. The ignition lock cylinder control actuator purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The column ignition lock system consists of an ignition lock cylinder control actuator, and a park position switch that is located in the automatic transmission shift lock control switch. The ignition lock cylinder control actuator contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.
There should be a hole in the bottom of plastic steering cover or a rubber cover that comes out . you can stick your finger up there an there is a button you push that will allow you to take out the key !
2006 chevy cobalt How to fix key being stuck in the ignition 2006 Impala shifter problems

Stuck ignition relay possible. With hot battery, turn key off and then feel each relay. If you find a hot one, change it.

I think the fault is with the radiator temp censer , it acts as a on off switch, located on the radiator tank.

make sure the starter is wired properly... you would be surprised how many people forget where the little wire from the solenoid goes.

NOTE: Your vehicle is equipped with a

brake-shift interlock feature. This

feature prevents you from shifting

from P (Park) unless you have the

brake pedal depressed. (The ignition

must be in the ON position.) If you

cannot shift from P (Park) with the

brake pedal depressed:

1. Apply the parking brake.

2. Remove the key.

3. Insert the key and rotate one position
clockwise (ignition in the OFF position).

4. Apply the brake pedal and shift to N

(Neutral). (If the vehicle is shifted to P

(Park), you must repeat the previous steps.)

5. Start the vehicle.

If you need to shift out of P (Park) by using the

alternate procedure described above, it is

possible that a fuse has blown and that your

brakelamps may also not be functional.

WARNING

DO NOT DRIVE YOUR VEHICLE UNTIL

YOU VERIFY THAT THE BRAKELAMPS
ARE WORKING.

check fuse 13 based on the attached diagram.

If this fuse is bad replace it. If it is not bad, blows again, or continues to be stuck in park then you need a new brake interlock switch that can be found on the brake pedal up underneath the dash.

Fig. 1: The blower motor and fan assembly is mounted in the heater and A/C module, and is accessible from the engine compartment

GM Bonneville/Eighty Eight/LeSabre 1986-1999
Blower Motor - REMOVAL & INSTALLATION
(see Figures 1 and 2)

1. Disconnect the negative battery cable.
2. If necessary, tag and disconnect the number 2, 4 and 6 spark plug wires from the ignition coil and move the coil out of the way.
3. For 1993-99 vehicles, remove the nuts and cross brace bar.
4. Detach the electrical connections from the blower motor.
5. Disconnect the cooling tube from the blower motor.
6. Unfasten the screws securing the blower motor to the blower module assembly.
7. Remove the blower motor and fan assembly from the module.
8. If necessary, unfasten the nut attaching the fan to the blower motor shaft, then pull the fan from the blower motor.

Fig. 2: You can disassemble the fan from the motor by removing the retaining nut


To install:

1. If the fan was removed from the motor, position the fan on the shaft, then install the retaining nut. Tighten the nut to 12 inch lbs. (1.4 Nm).
2. Position the blower motor and fan assembly to the module, then install the retaining screws. Tighten to 5 inch lbs. (0.6 Nm).
3. Connect the cooling tube to the blower motor.
4. Attach the electrical connector to the blower motor.
5. On 1993-98 vehicles, install the cross brace bar and retaining nuts. Tighten the nuts to 18 ft. lbs. (25 Nm).
6. If removed, install the coil and connect the spark plug wires, as tagged during removal.
7. Connect the negative battery cable.

Hope this helped (remember rated and comment this).

I just started experiencing the same problem. Yes, typically after rainy days, I can never get the interior lights to go out after the ignition key has been removed. The car acts as if there is a door open. Now, my latest problem is with the heater fan. Of course, putting the control in the "off" position will turn it off but you can turn it on and off with no ignition key installed. I'm also having problems with my heater core too so it's been a pain in the but!!

I believe this problem has also caused my battery to die which is why I'm on this site in the first place!! I can't get into the car with the keys and the dead battery won't allow me to unlock the car!! When it rains it pours!!!