1998 Expo Lop-sided rear suspension

One pump for entire system

I think you may have a bad air shock
or level control switch most likely on
lower control arm at rear,hope my guessing
help direct you in the right direction

Try Google & You Tube also

You need to take your car to a suspension specialist and also get them to check the front and rear wheel alignment.

What the back is to low or left and right side not even if you whant to lift the rear suspension air shocks

A sway bar is a suspension piece that keeps the left and right side of vehicle connected to help with turns. They are held together through sway bar links at each end, which are fairly common to break or rattle over bumps.

Below is the diagram you requested, courtesy of: http://the12volt.com

1998 Nissan Frontier Stereo Wiring

Constant 12V+ Pink

Switched 12V+ Blue

Ground Gray

Illumination Red/Blue

Dimmer Red/Yellow

Antenna Right Front

Front Speakers 6 1/2" Doors

Left Front (+) Pink

Left Front (-) Blue

Right Front (+) White

Right Front (-) Black

Rear Speakers 5" Side Panels

Left Rear (+) Light Green

Left Rear (-) Purple

Right Rear (+) Blue

Right Rear (-) Pink

Removal & Installation

1. If equipped, turn the air suspension service switch to the OFF position before raising the vehicle.
   
2. Drain the cooling system.
   

1. Remove or disconnect the following:
2. Negative battery cable
   

• Front seats
  
• Carpeting
  
• Rear airflow duct
  
• Heater hoses
  

1. Remove the driver’s side air bag module by removing or disconnect the following:
2. SRS module-to-steering wheel bolts, from both sides of the steering wheel.
   

• SRS module and disconnect the electrical connector
  
• Horn switch electrical connector
  

1. Remove the passenger’s side SRS module by removing or disconnecting the following:
2. Open the glove box and disconnect the glove compartment isolator
   

• Push inward on the 2 glove box door tabs and lower it
  
• SRS module’s electrical connector
  
• SRS module-to-instrument panel bolts and the module
  

1. Remove the instrument panel by removing or disconnecting the following:
2. Speed control servo nuts and move the servo aside
   

• Bolt and disconnect the left side bulkhead connector
  
• Left side bulkhead connector from the dash panel
  
• Windshield washer fluid reservoir screw, and position the reservoir aside
  
• Blower motor electrical connector
  
• Air conditioning pressure cut-off switch electrical connector
  
• In-line electrical harness connector
  
• Electronic Automatic Temperature Control (EATC) variable blower motor controller electrical connector
  
• Right front wheel
  
• Right front fender splash shield bolts and move the shield away from the cowl
  
• Wiring harness from the evaporator case
  
• Wiring harness from the cowl
  
• Right side instrument panel lower insulator pushpins, disconnect the power point electrical connector, remove the courtesy lamp from the socket and remove the insulator
  
• Unseat the wiring grommet and feed the wiring harness through the cowl
  
• Cowl side trim panels and the windshield side garnish moldings from both sides
  
• Locking clip and the Electronic Crash Sensor (ECS) module electrical connector
  
• Antenna connector
  
• Ground wire bolts from the right side
  
• EATC hose at the evaporator housing
  
• Bolt and disconnect the bulkhead connector from the right side
  
• Pull the door weatherstrip seals away from the instrument panel on both sides
  
• Tunnel brace trim cover
  
• Climate control head vacuum harness connector
  
• Instrument panel tunnel brace nuts and the brace
  
• Ground wire bolts from the left side
  
• Wiring harness connectors from the left side
  
• Parking brake switch electrical connector
  

• Pry out the instrument panel defroster opening grille, disconnect the electrical connectors and the remove the grille.
  

1. Remove or disconnect the following:
2. 3 upper instrument panel screws
   

• Instrument panel cowl side nut from both sides
  
• Instrument panel cowl side bolt. From the left side
  
• Instrument panel
  
• Windshield wiper mounting arm and the pivot shaft
  
• Electrical connector and remove the upper cowl extension screw and the extension
  
• Vacuum hoses and the wire harness connector from the evaporative emissions canister purge valve
  
• Evaporative emissions purge valve nuts and the valve
  
• Cowl side nut
  
• Right side rear fender apron screws and reposition the apron
  
• Evaporator housing nut and screw
  
• Vacuum hoses and the wiring harness connectors
  
• Plenum chamber’s lower flange nuts
  
• Plenum chamber’s upper flange nut and the plenum chamber
  
• Heater core cover-to-heater plenum chamber screws and the cover
  
• Seal and the heater core
  

have your suspension checked .blown struts can cause steering issues

If you have the coil spring suspension, then your spring for that corner has really sagged[doubtful] I suspect you actually have the rear air suspension ,and the air spring for the Right/Rear has lost air, allowing the rear end to lower down greatly. Usually, you need a new air spring when one develops a leak. You may or may not be able to see the leak with a spray solution of soapy water after the spring is removed for inspection. Sometimes you have to apply about 20psi of air pressure into the spring to inflate it a bit, then put the spring under water in a big enough tank/tub of water to catch the leak that way.

check to see if there is a ride height sensor in the rear of the truck and make sure that both side are even.

REAR WHEEL ALIGNMENT
TOE-IN : 0±2 mm (0±0.08 in.)
1. The rear suspension lower arm mounting cam bolt should be turned an equal amount on both sides during adjustment. Right wheel : Clockwise direction : toe-in Left wheel : Clockwise direction : ton-out Maximum difference between LH and RH : 3mm 2. The cam bolt should be adjusted within a 90° range left or right from the center position. CAMBER Standard value : 0°±30´ Maximum difference between LH and RH : 3mm : 0±2 mm (0±0.08 in.) 1. The rear suspension upper arm mounting cam bolt should be turned an equal amount on both sides during adjustment. 2. Install the left and right springs which have the same identification color. 3. The cam bolt should be adjusted within a 90° range left and right from the center position. TIRE WEAR 1. Measure the tread depth of the tires. Tread depth of tire [Limit] : 1.6 mm (0.06 in.) 2. If the remaining tread depth is less than the limit, replace the tire. When the tread depth of the tire is reduced to 1.6 mm (0.06 in.) or less, the wear indicators will appear.