Cannot find relay for door power lock - Regal Buick Cars & Trucks

Power windows don't use fuse's , has circuit breakers
• PWR WDO CB 25A (fuse block) (System power for left and right windows 2-door vehicles. System power for LF and LR windows 4-door vehicles)
• PWR WDO CB 25A (IP wiring harness junction block) (System power for RF and RR windows 4-door vehicles)

Door Lock System Components
The power door lock system consists of the following components:
• The driver door module (DDM)
• The passenger door module (PDM)
• The body control module (BCM)
• The driver information center (DIC)
• The rear door lock switch
• The door lock relay
• The door unlock relay
• The liftgate lock relay--utility vehicles with liftgate only
• The reversible door lock actuators in each of the doors and liftgate
• LOCKS 20A fuse (rear lock/unlock relay supply voltage)
• ECC 10A fuse (liftgate lock relay supply voltage)

Door Lock System Components
The power door lock system consists of the following components:
• Driver door module (DDM)
• Passenger door module (PDM)
• Door lock relay--Located in the instrument panel (I/P) fuse block and controls the locking of the rear doors.
• Door unlock relay--Located in the I/P fuse block and controls the unlocking of the rear doors
• Body control module (BCM)
• IP BEC
• Reversible door lock actuators in each door

Driver and Passenger Lock System Operation
The front power door lock switches are integral components of the driver door module (DDM) and passenger door module (PDM). The switches are two-position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitor these inputs and send a LAN message indicating a change in the switch position. Modules, that activate the power door lock motors, receive the LAN message and activate the motor in the appropriate direction to lock or unlock the vehicle doors. The body control module (BCM) upon receipt of a lock or unlock signal will control the rear door lock or unlock relays and also send a LAN message to the DDM and PDM to perform the commanded function.
The modules that activate the power door lock motors are:
• DDM (driver door lock actuator)
• PDM (passenger front door lock actuator)
• BCM (both rear door lock actuators)
The DDM and PDM are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other, causing the doors to lock or unlock.
The rear passenger doors are controlled by the BCM through the rear door lock/unlock relay which is incorporated onto the printed circuit board in the LH BEC. The BCM controls the unlock relay by providing ground to energize the coil and controls the lock relay by providing battery voltage to energize the relay coil. This energizes the relay and allows voltage to be applied to either the door lock motor lock or unlock circuits. Since the other side of the door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock or unlock.

A electrical short circuit keeps blowing the fuse . Looking at a wiring diagram an using a DVOM - digital volt ohmmeter to test the electrical circuits is how to find the problem . With not having the vehicle here to test i would only be guessing as to what the problem is . Plus you need to train to learn how to fix these type problems .
https://www.youtube.com/watch?v=SO-eKuhCOqc

https://www.youtube.com/watch?v=efKoWifdcag&t=4669s

You need to look an see what else that fuse powers ,fuse's sometimes power other thing's besides what the fuse is called .Power locks fuse # 32 20 amp. Does the car have keyless entry ?
xTooltipElement
Service Information
1999 Chevrolet Monte Carlo ' Monte Carlo, Lumina (VIN W) Service Manual ' Body and Accessories ' Doors ' Description and Operation ' Document ID: 292071
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Power Door Locks Circuit Description
Models Without Keyless Entry
When either door lock switch is pressed in the power door locks system, all doors lock or unlock in unison. Each lock can also be operated manually from the locking knob.
The locks are operated by reversible actuators that receive voltage from the door lock relay assembly's two built-in relays. The relays energize the actuators by applying voltage to one of the terminals and ground to the other terminal. In order to reverse the actuators, the polarity to the terminals is reversed.
The door lock switches are usually closed briefly. If the door lock switches are held closed, a circuit breaker in each actuator will open to protect against damage. The circuit breaker resets only after voltage is removed from the actuator.
Lock Operation
Pressing the lock position on either door lock switch sends a voltage signal in CKT 195.
Pressing the lock position turns on the lock relay located inside the door lock relay assembly. The lock relay completes the circuit that supplies voltage to CKT 295. CKT 295 is the voltage feed to the actuators.
At this time, the unlock relay is not energized. When the unlock relay is off, CKT 294 is grounded, which provides a ground path to the door lock actuators.
The entire action described completes the electrical circuit the actuators in each door, thus locking the doors.
When the door lock switch is released, the lock relay contact closes to ground, and the actuators turn off.
Unlock Operation
Pressing the unlock position on either door lock switch sends a voltage signal in CKT 194.
Pressing the unlock position turns on the unlock relay located inside the door lock relay assembly. The unlock relay completes the circuit that supplies voltage to CKT 294. CKT 294 is the voltage feed to the actuators.
At this time, the lock relay is not energized. When the lock relay is off, CKT 295 is grounded, which provides a ground path to the door lock actuator.
The entire action described completes the electrical circuit to the actuators in each door, thus unlocking the doors. The polarity of the voltage to the actuators has reversed, causing the actuators to run in the opposite direction in order to unlock the doors.
Models Equipped With Keyless Entry
All door locks operate the same as vehicle models equipped without keyless entry, except the left front door lock.
Lock Operation
Pressing the lock position on either door lock switch sends a voltage signal in CKT 195.
Pressing the lock position turns on the lock relay located inside the door lock relay assembly. The lock relay completes the circuit that supplies voltage to CKT 295. CKT 295 is the voltage feed to the actuators.
At this time, the lock relay is not energized. When the lock relay is off, CKT 295 is grounded, which provides a ground path to all door lock actuators, except left front door lock actuator.
The left front door actuator is grounded through the Remote Control Door Lock Receiver, RCDLR, CKT 694. The RCDLR has a built-in relay. When the built-in relay is de-energized, the relay provides a path to ground to the left front door actuator.
The entire action described completes the electrical circuit to the actuators in each door, thus locking the doors.
When the door lock switch is released, the lock relay contact closes to ground, and the actuators turn off.
Unlock Operation
Pressing the unlock position on either door lock switch sends a voltage signal in CKT 194. The signal is sent to both the unlock relay located inside the door lock relay and the Remote Control Door Lock Receiver, RCDLR.
Pressing the unlock position turns on the unlock relay, and signals the RCDLR to unlock the left front door. the unlock relay completes the circuit that supplies voltage to CKT 294. CKT 294 is the voltage feed to the actuators, except the left front door lock actuator.
The left front door actuator receives voltage through the Remote Control Door Lock Receiver, RCDLR, CKT 694. the RCDLR has a built-in relay. When the built-in relay is energized, the relay provides a voltage to the left front door actuator. The RCDLR energizes the relay when it receives a voltage in CKT 194.
At this time, the lock relay is not energized. When the lock relay is off, CKT 295 is grounded, which provides a ground path to all door lock actuators.
The left front door actuator is grounded through the Remote Control Door Lock Receiver, RCDLR, CKT 694. The RCDLR has a built-in relay. When the built-in relay is de-energized, the relay provides a path to ground the left front door actuator.
The entire action described completes the electrical circuit to the actuators in each door, thus locking the doors.
When the door lock switch is released, the unlock relay contact closes to ground, the RCDLR left door unlock control relay contacts close to ground, and the actuators turn off.

You can find free wiring diagrams here
http://www.bbbind.com/tsb-wiring-diagrams-database/

I imagine you checked the fuse.

Gremlins ! HA HA HA sorry ! First off a little bit on how they work an what all is involved in making them work ! There are a few control modules in the mix , switches ,relays etc...
Door Lock System Components
The power door lock system consists of the following components:
?€¢
The driver door module (DDM)

?€¢
The passenger door module (PDM)

?€¢
The body control module (BCM)

?€¢
The driver information center (DIC)

?€¢
The rear door lock switch

?€¢
The door lock relay

?€¢
The door unlock relay

?€¢
The liftgate lock relay--utility vehicles with liftgate only

?€¢
The reversible door lock actuators in each of the doors and liftgate

?€¢
LOCKS 20A fuse (rear lock/unlock relay supply voltage)

?€¢
ECC 10A fuse (liftgate lock relay supply voltage)

Door Lock System Controls
The power door lock system can be controlled by any of the following:
?€¢
A power door lock or unlock switch activation

?€¢
A keyless entry transmission

?€¢
An automatic door lock function

?€¢
A delay lock function

?€¢
Door lock cylinder switch activation

?€¢
Lockout Prevention

?€¢
An airbag deployment

The front power door lock switches are integral components of the driver door module (DDM) and passenger door module (PDM). The switches are two position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitors these inputs and sends a Class 2 message indicating a change in the switch's respective position. Modules which activate the power door lock motors receive the Class 2 message and activate the motor in the appropriate direction to lock or unlock the vehicle's doors and liftgate. The rear door lock switch provides a lock and unlock signal to the body control module (BCM). The BCM upon receipt of a lock or unlock signal will control the rear door lock relays and also send a Class 2 message to the DDM and PDM to perform the appropriate function.
The modules which activate the power lock motors are:
?€¢
The DDM (driver door lock actuator).

?€¢
The PDM (passenger front door lock actuator).

?€¢
The BCM (both rear door lock actuators and cargo door/liftgate).
The DDM and PDM are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other causing the doors to lock or unlock.
The rear passenger and cargo doors differ slightly in that they use lock and unlock relays. The relays supply and coil sides receive a constant voltage through the battery voltage supply circuit. The normally closed contacts are connected to ground and the control side is connected to the BCM. Once a door lock or unlock request has been received by the BCM, the BCM will ground the control side of the appropriate relay. This energizes the relay and allows voltage to be applied to either the door lock motor lock or unlock circuits. since the other side of the door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock or unlock.
The first place to start is have a factory or equivalent scan tool hooked up , one that can read BCM DTC'S - diagnostic trouble codes ! This could lead to a fix faster ! Watch these three videos !
Door Locks Go Crazy 1

The power lock relay can be found under the hood in the power train fuse compartment or in the door just inside the door panel but mainly under the hood in the bigger fuse box

Power Door Locks Circuit Description
The power door lock system incorporates door lock switches on both front doors and on the RH D-pillar, door lock motors in all passenger doors and in the RR cargo door, a door lock relay and a door lock control module.
Power for the door lock switches and the door lock control module is supplied from the CIG LTR fuse 13 through CKT 640 (ORN). Power for the door lock relay is supplied from the PWR ACCY circuit breaker through CKT 540 (ORN). Ground for the door lock relay is supplied from G202 through CKT 150 (BLK) and ground for the door lock control module is supplied from G400 through CKT 150 (BLK).
The door lock motors are reversible and both sides are connected to the normally closed contacts of the door lock relay. Those contacts of the relay are connected to G202. When any of the door lock switches are placed in the lock position, voltage is supplied through CKT 195 (LT BLU) to the relay lock coil. Since the other side of the lock coil is connected to ground, the coil is energized and it pulls the lock contacts closed. Voltage is then supplied through CKT 295 (GRY) to all the door lock motors and the doors lock. The unlock function operates in much the same manner except that when any of the switches are placed in the unlock position, voltage is supplied through CKT 194 (WHT) to the unlock coil of the relay and CKT 294 (TAN) supplies voltage to the apposite side of the door lock motor and the doors unlock.
Door Lock Control Module Description
The door lock control module is used on vehicles equipped with cargo doors. The purpose of the module is to lock the cargo doors after a lock cycle has been commanded from any of the door lock switches with the cargo doors open. When the RH cargo door is open, the module receives a ground signal from the closed contacts of the rear door jamb switch on CKT 1897 (ORN/BLK) to G400. When a lock command is received, the module retains this input until it receives an open input from the rear door jamb switch. Then the module sends a lock command through CKT 194 (WHT) to the door lock relay and the doors lock.
Rear Cargo Doors Description
The power door lock motor will not operate unless the rear cargo doors are fully closed. The power door lock motor is in the right cargo door. The contactors are on the rear cargo door opening on the body and on the right cargo door.

Power is supplied to the Power windows and sunroof through the power window circuit breaker. That circuit breaker is supplied power through the RAP (retained accessory power) Relay, the RAP relay also supplies power to the radio. The RAP relay is also fuse protected by the RAP fuse in the under hood fuse block. The RAP relay is energized by the BCM body control module.

The RAP relay is responsible for the radio and windows working after the igntion is turned off.

The first place to check would be the RAP fuse in the under hood fuse block and then the RAP relay in the Body fuse block.

A list of the BODY relay block located on the left side of the dash to the right of the interior fuse block is below:

(1) Park Lamp Relay (2) Courtesy Lamp Relay (3) Retained Accessory Power (RAP) Relay (4) Power Seats Circuit Breaker (5) Power Windows Circuit Breaker (6) Inadvertent Power Relay (7) Door Lock Relay (8) Headlamp Ground Relay (9) Driver Door Unlock Relay (10) Door Unlock Relay(1) Park Lamp Relay
(2) Courtesy Lamp Relay
(3) Retained Accessory Power (RAP) Relay
(4) Power Seats Circuit Breaker
(5) Power Windows Circuit Breaker
(6) Inadvertent Power Relay
(7) Door Lock Relay
(8) Headlamp Ground Relay
(9) Driver Door Unlock Relay
(10) Door Unlock Relay
(1) Park Lamp Relay (2) Courtesy Lamp Relay (3) Retained Accessory Power (RAP) Relay (4) Power Seats Circuit Breaker (5) Power Windows Circuit Breaker (6) Inadvertent Power Relay (7) Door Lock Relay (8) Headlamp Ground Relay (9) Driver Door Unlock Relay (10) Door Unlock Relay (1) Park Lamp Relay (2) Courtesy Lamp Relay (3) Retained Accessory Power (RAP) Relay (4) Power Seats Circuit Breaker (5) Power Windows Circuit Breaker (6) Inadvertent Power Relay (7) Door Lock Relay (8) Headlamp Ground Relay (9) Driver Door Unlock Relay (10) Door Unlock Relay

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Found this answer in anotherr forum and works for me. Power Door Lock Relay Location

Aux Relay Box #4 is in the rear driver's side removable panel with the tire jack.

This Relay box holds the Door Lock / Unlock relays (ice cube type). It also holds the Driver Door Unlock Relay and the ACC Lights Relay (rectangular relays).

if you can here relays when unlocking/locking check for power at door lock actuators inside doors, if you have power on lock/unlock and good earth from connector actuators are faulty.
if no power on test light when operating check output from central door lock module while operating, none coming out of module then it might need replacing.
check 30Amp power fuse for main relay under bonnet (which goes to pin 8 white/blue on module)and 10Amp gauge fuse in cab(pin 1 blue/red on module),pin 15 is also power when relay is on(red/blue) with test light, and module/ actuators.
check outputs from module pin 3 & 4
blue/red
blue/black
that go to door locks