2001 Nissan Xterria, the brake lights is on when the vehicle is off

For which component or system?

misadjusted brake light switch or is it the dash brake light then fluid level is low

Does it say 'emergency brake' or just 'brake'? If it just says brake, you could be low on brake fluid on your 2001 Nissan Xterra.----------------------------------------------------------------------------------
KESS V2 OBD2 Manager Tuning

What is wrong with your vehicle ? I am a Nissan tech and I am not sure what your are looking for.

power steering flush antifreese flush brake fluid flush check pads thickness replace belts oil change change transmission fluid check ac charge and check for fluid leaks check the timing replace timing belt check lights check the shocks struts check tire pressure and thickness

some vehicles have a warning light when the barkes need replacing. the brake light staying on could be this or the sensor for the parking brake may be bad.

Check looseness or corrosion on the leads and wiring at the battery terminals. Check for looseness or corrosion on the alternator connectors. With vehicle started and reved to 2000RPM, use a voltmeter to measure voltage and that measurement should be between 13.5-14.8. If you're unable to achieve this voltage have your alternator checked at autozone or advance auto, its free. Hopefully this helps

It does not have an expansion valve. It uses a fixed orifice tube in the line. They seldom go bad (get plugged).

What are your symptoms that make you think you have a bad orifice?

The a/c system compressor should cycle on and off about 4 times/minute at 70 degrees F. AT 90 F, it should stay engaged all the time. The on/off control is a pressure switch, usually on the accumulator bottle.

The hard part is pressing the caliper piston abck into the caliper so you can get the new, thicker pads over the rotor. A large C Clamp works best.

SECTION 206-03: Front Disc Brake 2001 Villager Workshop Manual
REMOVAL AND INSTALLATION Pads —Front Disc Brake Removal

1. Remove the wheel and tire assembly. For additional information, refer to Section 204-04 .

1. Remove the front disc brake caliper bolts. torx bit. T20?

1. Support the front disc brake caliper from the front strut and spring assembly using mechanics wire.

1. Remove the front disc brake pads.
   1. Remove the outboard front disc brake pad.
   1. Remove the inboard front disc brake pad.

Installation

1. CAUTION: Make sure the master cylinder reservoir does not overfill and spill brake fluid while retracting the front disc brake caliper piston.
   NOTE: It is necessary to fully retract the front disc brake caliper piston in the bore before installing the front disc brake pads.
   Install the front disc brake pads.
   1. Install the inboard front disc brake pad.
   1. Install the outboard front disc brake pad.

Caution. The outer pads are left and right. put left on driver side.

1. Position the front disc brake caliper on the front-wheel knuckle and install the brake caliper pin bolts.

1. WARNING: It is necessary to depress the brake pedal several times to position the front disc brake caliper piston before driving the vehicle.
   

Alternator failure