A heater core is much like a small radiator. Coolant is circulated through it from the water pump, and it has fins to increase the surface area and shed heat more efficiently. Signs that a heater core needs to be replaced are.
Heater Core for Toyota Pickup 1989-1995 T100 1993-1998 w/ Standard Duty Heater
Heater Core for Toyota Pickup 1989-95/T100 1993-1998 w/Standard Duty Heater ASI
Heater Core For Toyota 1989-1995 Pickup 1993-1998 T100 w/Standard Duty Heater
Heater Core For Toyota Pickup 1989-1995 /1993-1998 T100 + Standard Duty Heater
Heater Core For Toyota 1989-1995 94 Pickup/1993-1998 T100 w/Standard Duty Heater
Heater Core For Toyota Pickup 89-95/T100 93-98 w/Standard Duty Heater Quality US
