Tom

Tom,

Q I have a 1990 Ford Ranger with a 2.3 engine. My heater blows lukewarm

air. I installed a new thermostat, a new water pump, and a new radiator, and I
am still getting lukewarm air!! Any help you can give me will be greatly
appreciated.

Thanks, Dan—Madison,    Wisconsin

Dan,

A Based on what you have done on the vehicle to this point, it would

appear the problem might be traced to a plugged or restricted heater core.
The heater core is a mini-radiator located in the passenger compartment that
heats the air forced over it by the blower motor. The heater core could be
compared to the steam radiators in an old house. Without a good flow of hot
water through the core, there isn’t enough heat to transfer to the air. Testing
the core is as easy as feeling the heater hoses. If both hoses are good and hot
(provided the cooling system is full), the core is probably OK. If one is hot
and the other one is significantly cooler, it’s likely the core is either restricted
or plugged. Sometimes back flushing the core will remove the accumulated
sediment, restoring the proper flow. However, more often than not on the
Ranger and Explorer models, the core will need to be replaced. Success to
you.