I took positive battery cable off to install new fog lights,now my remote door lock won't work,can u help me?I have a 96 Nissan pathfinder 5speed 4wd v6

Disconnect the negative cable first and then the positive cable and remove the battery. The lights/alarm will go out when battery is disconnected and may come back on when reconnected. Use door lock key fob to shut alarm/lights off if they come back on when battery is reconnected

The Central Timer Module (CTM, called BCM on some vehicles) supports or controls:
Automatic door lock/central locking
Battery protection
Chimes
Exterior lights (park lamps, fog lamps, headlamps)
Interior lights
Intermittent wiper control
Power lock control
Remote keyless entry (RKE)
Vehicle Theft Security System (VTSS)
Remote radio control (from steering wheel)

It covers all the problems you described except the 4WD controls. I suspect you may want to have the CTM checked, or do like I did and just replace it (used about $75-$100 on eBay). Make sure you get the part number on yours and match the number portion (not necessarily the two letter suffix) EXACTLY.
It should be located behind the kick panel to the left of the driver's feet (that's where it is on my 2003 Dakota), but may be to the right of the glove box (have to remove the glove box to get to it).

I couldn't turn off the security alarm on my 1999 Pathfinder as I replaced the battery,
Solution: I read the solution here to disconnect the positive cable, open the driver's door, insert the key, then reconnected the positive cable, while honking, I turn the key to the left, to the right and to the left again while the door is still open. The honking stopped. Then I started the truck without a problem. Thank you for the hint.

Battery Constant 12v+ Positive Wire (+): Black/Yellow
Battery Constant 12v+ Positive Wire Location: Ignition Switch Harness

Starter Positive Wire (+): Blue/Red
Starter Positive Wire Location: Ignition Switch Harness

Ignition Positive Wire (+): Red
Ignition Positive Wire Location: Ignition Switch Harness

Accessory Positive Wire (+): Red/Yellow
Accessory Positive Wire Location: Ignition Switch Harness

Parking Light Positive Wire (+): Red
Parking Light Positive Wire Location: Low In Drivers Kick Panel

Power Door Lock Negative Wire (-): Add Actuator. This vehicle uses a central door locking system. When connecting a keyless entry, you will need to add a door lock actuator and some units will also require (2) extra relays.
Power Door Lock Negative Wire Location: To Drivers Door Only

Power Door Unlock Negative Wire (-): Add Actuator. This vehicle uses a central door locking system. When connecting a keyless entry, you will need to add a door lock actuator and some units will also require (2) extra relays.
Power Door Unlock Negative Wire Location: To Drivers Door Only

Door Trigger Negative Wire (-): Red/White
Door Trigger Negative Wire Location: In Black Plug, Above Hood Release

Domelight Supervision Wire: Use Door Trigger, Requires Relay
Domelight Supervision Wire Location: N/A

Horn Negative Wire (-): Red/Green
Horn Negative Wire Location: At Steering Column Harness

Tachometer Wire Negative Wire (-): Black/Blue
Tachometer Wire Negative Wire Location: At ECM, Under Drivers Side Dash

Brake Light Positive Wire (+): White/Black
Brake Light Positive Wire Location: At Switch Above Brake Pedal

CODE ALARM SYSTEM

Used on:
Impreza 1996-2001
Legacy 1995-1999
Forester 1998-2000

Battery GP-23A

Lock: Left button will lock all doors. Double chirp indicates locked.
Unlock: Right button will unlock driver's door only. Hold unlock button app 6 seconds, it will unlock all doors including rear gate. Single chirp indicated unlock.
If the car chirps or lights flash 4x the alarm was triggered.
Panic. Press both buttons to activate emergency honk and flashing lights.
Valet mode: With optional alarm onlyPress the red alarm button on the left of the steering wheel. The light will quickly double flash. To re-set back to normal mode, press the red alarm light button again

Battery failed and lights flashing?
Parking lights will flash when the vehicle's battery is disconnected and reconnected.
To stop lights from flashing, either:
Press remote transmitter "UNLOCK" button once OR turn the ignition switch to the "ON" position and press programming button for one second (see below).
The vehicle interior (courtesy) light and door open warning light (DOOR AJAR indicator) will then illuminate for 60 seconds when the ignition is turned off, or until the doors are locked with the remote transmitter. Yes, the dashboard instrument panel lights will flash when the parking lights flash.

Programming or Overriding the Alarm when you have lost the remote
Open driver's door.
Turn ignition key to 'On'
Press and *hold programming button* in (see diagram, button under dashboard)
After 15 seconds the the door locks will cycle 3 times. Do not release Programming button.
Press lock (left) button the remotes to be programmed. The door locks will cycle one time. Exit programming mode by releasing Programming button under dashboard and turning key to off.

Code Alarm Programming Button is under dashboard on the kick panel by the driver's left knee, left of the steering column. If you can't find it, it might still be tucked up in the wiring harness higher up in that same general area. The botton is recessed in a plastic ring (see diagram).
This button must be pressed while programming remotes or if the battery was disconnected and the lights are flashing.

Cut where the latch connects with a sawzall. Replace latch post whee the latch articulates.

Nissan Pick-ups and Pathfinder 1989-1995
Starter - REMOVAL & INSTALLATION
(see Figures 1 and 2)

1. Disconnect the negative battery cable at the battery, then disconnect the positive battery cable at the starter.
   

Fig. 1: Starter removal on 4WD-6-cylinder engine



Fig. 2: Starter removal on 2WD-6-cylinder engine

1. On 4wd models with the 6-cylinder engine:
   1. Remove the front gravel shield.
   2. Detach the oil pressure switch connector.
   3. Drain the engine oil and remove the oil filter.

CAUTION The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

1. On 2wd models with the 6-cylinder engine:
   1. Remove the front right wheel.
   2. Remove the front gravel shield.
   3. Remove the exhaust manifold heat insulator.
   4. Remove the exhaust manifold.
   5. Detach the oil pressure switch connector.
   
   
2. Unfasten the remaining electrical connections at the starter solenoid.
3. Remove the two nuts holding the starter to the bell housing, then pull the starter toward the front of the vehicle and out.

Hope this help (remember rated this).

Sound's like there is a short in the wiring and it is either getting a positive connection through the ground but if you take it to a shop they can tell you more cause they can test it for you

check fuse for low beam, then possibly both low beam globes. they could have blown.
the key remote may need reprograming into system try put key in ignition in on position then press remote buttons a couple of times then try if no good need to go to dealer to be programed into system again or it needs repairing/replacing.

Try this it works for the 95 and 96 models it should also work for all models 95 thru 99. 1st you need to get in the car and hit the lock button on the drivers door switch. Make sure doors and windows are all shut. To program the remote you must insert the key into the ignition 6 to 8 times rapidly in a 10 second time period and when you have done it correct the hazards lights will then illuminate twice. Next then you must hit the lock button quickly on the remote due to a slight time delay only hit the button once. Keep repeating this step until it works and to find out if it worked hold down the trunk button or the unlock button(the front windows should let down on you Mad-Max.

I would check the ignition switch