Engine light is not switching off while driving

Odometer
The instrument panel cluster (IPC) displays a season odometer and a trip odometer. Momentarily press the trip/reset switch in order to toggle between the season odometer and the trip odometer. Press the trip/reset switch for greater than 2 seconds, while the trip odometer is displayed, in order to reset the trip odometer. The odometer is calculated and stored electronically in the body control module (BCM). The BCM uses the vehicle speed information from the engine control module (ECM) to calculate the odometer. The odometer displays 'error' if an internal IPC memory failure is detected. The IPC stores a backup copy of the odometer value incase the IPC stops receiving a valid odometer value from the BCM. The odometer will display 'error' if an internal IPC memory failure is detected.

Your best bet , take it to a qualified repair shop .

Try 2004 buick rendezvous fuse box diagram Google Search

Before doing something drastic ,have it checked out for DTC'S - diagnostic trouble codes . It may not be the anti-theft system ,gauges going flat would be more like a communication problem between modules . PCM / BCM / instrument cluster etc.. That also could cause theft light coming on . If your not sure what to look for ,take it to a ASE certified professional . You may render your vehicle useless if you don't know what your doing .
Serial Data Power Mode Master
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle, the PMM is the body control module (BCM). The PMM receives 3 discrete ignition switch signals to differentiate which power mode will be sent over the Serial Data circuits. The 3-wire Ignition Switch table below illustrates the state of these inputs in correspondence to the ignition switch position:
Serial Data Messages The modules that depend exclusively on serial data messages for power modes. stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to RUN. In this state, the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state, the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.
Indicators and Warning Messages
Refer to Indicator/Warning Message Description and Operation .
Engine Coolant Temperature Gage
The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC receives a serial data message from the PCM/ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 38?°C (100?°F) if:
?€¢
The PCM/ECM detects a malfunction in the engine coolant temperature sensor circuit.

?€¢
The IPC detects a loss of serial data communications from the BCM.

Fuel Gage
The instrument panel cluster (IPC) displays the fuel level as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC receives a serial data message from the body control module (BCM) indicating the fuel level. The fuel gage defaults to E (empty) if:
?€¢
The PCM/ECM detects a malfunction in the fuel level sensor circuit.

?€¢
The IPC detects a loss of serial data communications from the BCM.

When the fuel level is less than 14 percent, the low fuel indicator illuminates.
Odometer
The instrument panel cluster (IPC) contains a season odometer and a trip odometer. Momentarily press the trip/reset switch in order to toggle between the season odometer and the trip odometer. Press the trip/reset switch for greater than 2 seconds, while the trip odometer is displayed, in order to reset the trip odometer. The odometer is calculated and stored electronically in the body control module (BCM). The BCM uses the vehicle speed information from the powertrain control module (PCM) to calculate the odometer. The odometer displays 'error' if an internal IPC memory failure is detected. The IPC stores a backup copy of the odometer value incase the IPC stops receiving a valid odometer value from the BCM.
Speedometer
The instrument panel cluster (IPC) displays the vehicle speed based on the information from the ECM/PCM. The IPC receives the vehicle speed information from the BCM via the serial data circuit. The speedometer defaults to 0 kmh (0 mph) when the following occurs:
?€¢
The powertrain control module (PCM) or the engine control module (ECM) detects a malfunction in the vehicle speed sensor circuit.

?€¢
The IPC detects a loss of serial data communication from the BCM.

Tachometer
The instrument panel cluster (IPC) displays the engine speed as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC receives a serial data message from the body control module (BCM) indicating the engine speed. The tachometer will default to 0 RPM if:
?€¢
The PCM/ECM detects a malfunction in the engine speed sensor circuit.

?€¢
The IPC detects a loss of serial data communication from the BCM.

Constant 12V+ Orange Switched 12V+ Yellow Ground Black Illumination Gray Dimmer Brown Antenna Trigger Pink Antenna Right Rear Front Speakers 6 1/2" Doors Left Front (+) Tan Left Front (-) Gray Right Front (+) Light Green Right Front (-) Dark Green Rear Speakers 6 1/2" Side Panels Left Rear (+) Brown Left Rear (-) Yellow Right Rear (+) Dark Blue Right Rear (-) Light Blue

Hope this helps:- Factory Disarm Purple/Yellow (-) Driver's Kick Panel Black Connector at ECM -slice into this wire, & wire it to ground, this disables the alarm.
Cavity/Fuse Diagram (1996 Grand Cherokee, passenger side kick plate to find, Owner's Manual pgs 205-206): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Row 1: 1-6 (left to right) Row 2: 7-12 Row 3: 13-18 Row 4: 19-22
1996 Jeep Grand Cherokee Fuse Panel (Passenger Side kick panel) Reply

CAVITY FUSE DESCRIPTION 1 -10 amp (RED) Radio 2 -15 amp (Lt Blue) Cigarette Lighter 3 -10 amp (RED) Rear Washer Switch, Body Controller 4 -10 amp (RED) Airbag 5 -10 amp (RED) Lamp Out Module, Overdrive Switch, OBD II 6 -15 amp (Lt Blue) Vehicle Information Center/Graphic Display Module Park & Side Lamps, Overhead Console Lighted Visor, Automatic Dimming Mirror 7 -20 amp (Yellow) Body Amp, Cluster, Body Controller 8 -20 amp (Yellow) Rear Wiper Motor, Flipper Glass Solenoid, Cargo Lamp, Trailer Tow 9 -15 amp (Lt Blue) Brake Switch 10- 10 amp (RED) Rear Window Defroster 11 -10 amp (RED) ABS Module 12 -10 amp (RED) Heater-Ventilation-A/C Control & Recirculation Motor 13 -15 amp (Lt Blue) Hazard Switch, Turn Signal Switch 14 -15 amp (Lt Blue) Spare 15 -15 amp (Lt Blue) Spare 16 -10 amp (RED) Right & Left Courtesy Lamp, Glove Box Lamp, Halo Lamp Cargo Lamp, Underhood Lamp, Dome/Read Lamp Right & Left Visor, Automatic Dimming Mirror 17 -15 amp (Lt Blue) Radio Illumination, Tail Lamp, Graphic Display Module, Park & Side Lamps, Headlamp Switch, Body Controller 18 -20 amp (Yellow) Spare 19 -15 amp (Lt Blue) Passing Light 20 -15 amp (Lt Blue) Radio, Heater-Ventilation-A/C, Vehicle Information Center 21 -15 amp (Lt Blue) Power Outlet 22 -10 amp (Blue) Airbag Module -------------------------------------------------------------------------------------
1996 Jeep Grand Cherokee Alarm, Remote Starter, Keyless Entry Wiring Information Constant 12V+ Pink/Black Ignition Switch Harness Starter Yellow Ignition Switch Harness Ignition Dark Blue/Gray Ignition Switch Harness Ignition 2 Red/Black Ignition Switch Harness (for AC) Accessory Black/Orange Ignition Switch Harness Tach Gray/White Coil Brake Switch White/Tan Brake Switch Trunk Pin n/a Works with Dome Light Parking Lights Blue/Red (+) Left of Steering Column or Light Switch Head Lamp Tan/Black Light Switch Factory Disarm Purple/Yellow (-) Driver's Kick Panel Black Connector at ECM -slice into this wire, & wire it to ground, this disables the alarm. Door Trigger Yellow (-) Driver's Kick Panel see notes Door Lock 5/Wire in Driver's Inside Driver's Door Orange/Purple Lock Pink/Black Unlock Door Unlock and Passenger's Doors Inside Passenger's Door Black/White L Pink/Black Unlock Horn Wire Gray/Orange (-) Steering Column Windows Up LF=Light Blue, RF=Brown/White, LR=Blue/White, RR=Gray/Black Doors Windows Down LF=White, RF=Purple/White, LR=Red/Black, RR=Green/White
• Cruise Control Information • Stereo Information • View all Jeep Vehicles

Hope this helps:
Cavity/Fuse Diagram (1996 Grand Cherokee, passenger side kick plate to find, Owner's Manual pgs 205-206): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Row 1: 1-6 (left to right) Row 2: 7-12 Row 3: 13-18 Row 4: 19-22
1996 Jeep Grand Cherokee Fuse Panel (Passenger Side kick panel) Reply

CAVITY FUSE DESCRIPTION 1 -10 amp (RED) Radio 2 -15 amp (Lt Blue) Cigarette Lighter 3 -10 amp (RED) Rear Washer Switch, Body Controller 4 -10 amp (RED) Airbag 5 -10 amp (RED) Lamp Out Module, Overdrive Switch, OBD II 6 -15 amp (Lt Blue) Vehicle Information Center/Graphic Display Module Park & Side Lamps, Overhead Console Lighted Visor, Automatic Dimming Mirror 7 -20 amp (Yellow) Body Amp, Cluster, Body Controller 8 -20 amp (Yellow) Rear Wiper Motor, Flipper Glass Solenoid, Cargo Lamp, Trailer Tow 9 -15 amp (Lt Blue) Brake Switch 10- 10 amp (RED) Rear Window Defroster 11 -10 amp (RED) ABS Module 12 -10 amp (RED) Heater-Ventilation-A/C Control & Recirculation Motor 13 -15 amp (Lt Blue) Hazard Switch, Turn Signal Switch 14 -15 amp (Lt Blue) Spare 15 -15 amp (Lt Blue) Spare 16 -10 amp (RED) Right & Left Courtesy Lamp, Glove Box Lamp, Halo Lamp Cargo Lamp, Underhood Lamp, Dome/Read Lamp Right & Left Visor, Automatic Dimming Mirror 17 -15 amp (Lt Blue) Radio Illumination, Tail Lamp, Graphic Display Module, Park & Side Lamps, Headlamp Switch, Body Controller 18 -20 amp (Yellow) Spare 19 -15 amp (Lt Blue) Passing Light 20 -15 amp (Lt Blue) Radio, Heater-Ventilation-A/C, Vehicle Information Center 21 -15 amp (Lt Blue) Power Outlet 22 -10 amp (Blue) Airbag Module -------------------------------------------------------------------------------------
1996 Jeep Grand Cherokee Alarm, Remote Starter, Keyless Entry Wiring Information Constant 12V+ Pink/Black Ignition Switch Harness Starter Yellow Ignition Switch Harness Ignition Dark Blue/Gray Ignition Switch Harness Ignition 2 Red/Black Ignition Switch Harness (for AC) Accessory Black/Orange Ignition Switch Harness Tach Gray/White Coil Brake Switch White/Tan Brake Switch Trunk Pin n/a Works with Dome Light Parking Lights Blue/Red (+) Left of Steering Column or Light Switch Head Lamp Tan/Black Light Switch Factory Disarm Purple/Yellow (-) Driver's Kick Panel Black Connector at ECM Door Trigger Yellow (-) Driver's Kick Panel see notes Door Lock 5/Wire in Driver's Inside Driver's Door Orange/Purple Lock Pink/Black Unlock Door Unlock and Passenger's Doors Inside Passenger's Door Black/White L Pink/Black Unlock Horn Wire Gray/Orange (-) Steering Column Windows Up LF=Light Blue, RF=Brown/White, LR=Blue/White, RR=Gray/Black Doors Windows Down LF=White, RF=Purple/White, LR=Red/Black, RR=Green/White
• Cruise Control Information • Stereo Information • View all Jeep Vehicles

Constant 12V+ Brown/White
Switched 12V+ Orange
Ground Black/Light Green
Illumination Pink/Black
Dimmer Pink
Front Speakers 5" x 7" Doors
Left Front (+) Gray/Blue
Left Front (-) Yellow/Blue
Right Front (+) Blue
Right Front (-) Yellow
Rear Speakers 5" x 7" Side Panels

Left Rear (+) Blue/White
Left Rear (-) Blue/White
Right Rear (+) Blue/Black
Right Rear (-) Red/Blue

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Constant 12V+ Light Green Switched 12V+ Black/Yellow Ground Black Illumination Blue/Yellow Dimmer n/a Antenna Right Front Front Speakers 4" Doors Left Front (+) Green Left Front (-) Blue/Red Right Front (+) Light Green/Yellow Right Front (-) Black/Green Rear Speakers 6 1/2" Side Panels Left Rear (+) Green/Yellow Left Rear (-) Blue/Orange Right Rear (+) Green/White Right Rear (-) Green/Blue