Location

• The blower motor on an air-conditioning-equipped 1990 Wrangler is located on the top of the evaporator core housing, behind the dashboard. On Wranglers without air conditioning, the blower motor is located on the rear of the heater housing. Removal of the heater housing is required to access the motor.
  
  

Safety First

• When removing the blower motor, or any electronic component, it is best to remove the negative battery cable from the battery first. This prevents accidental shorting of the electrical system while removing or installing components.
  
  

Function

• The blower motor is a small electric motor with an axle in the middle. When turned on, a small fan that attaches to the motor's axle spins, blowing air through the heater core or the evaporator core, depending on the temperature setting.
  
  

Precautions

• When removing the blower motor on a Wrangler without air conditioning, you must drain the coolant first. Coolant is highly toxic, so clean up any spills immediately and keep the coolant away from animals and children.
  
  

Refilling The Coolant

• Since draining the cooling system is required for units without air conditioning, you must fill the cooling system appropriately. The 2.5-liter-equipped 1990 Wrangler requires a 50/50 mixture of green anti-freeze and clean water totaling 9 quarts. The 4.2-liter Wranglers require the same 50/50 mix of green anti-freeze and clean water, but the system's capacity is 10.5 quarts. Remember to bleed the air from the cooling system after refilling it.