Jim Grant's Tech Tips
'95 Ford Escort, Great A/C No Heat
Q:
I bought a 95
Ford Escort LX 4dr for my daughter. The AC works great. The problem is
the heater blows but never gets warm. Any clues? How do we fix it?
- William
A:
There are a few possible
causes that come to mind for your no heat condition. The first check you
have to make is to prove that the cooling system is warming to the correct
operating temperature. It is not uncommon for a failing thermostat (one
that is opening too soon or stuck open) to cause the coolant and engine
to operate at a low temperature. This reduces gas mileage and the heat
from the heater. If the thermostat proves to be operating correctly then
the flow of coolant to and from the heater core should be checked. A quick,
but not perfect test is to check the temperature of the coolant hoses
to and from the heater core. A restricted or plugged heater core will
cause one of the coolant hoses to be markedly cooler than the other. A
restricted or plugged heater core is not uncommon on a vehicle of your
age. If the heater proves to be restricted be sure to have the cooling
system flushed. The passages in heater cores are very small and a poorly
maintained cooling system is sure fire to plug these passages. Weve
seen brand new heater cores plugged just as bad as the old ones because
of contaminated cooling systems. Last, but possible, is a control problem
inside the heater box. There are doors that are used to blend and direct
the air. If one of these blend doors is not operating correctly your heating
system would only be a cooling system.
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