Toyota Trucks: 2000 4 runner heater not heating up

"michaelthomas70" <com> wrote in message
news:talkaboutautos.com... 
my therm. and also flushed out and filled my coolant. My heater control
valve seems to be working. Could my heater core be clogged? Could the
sensor switch be bad? My window defrost are not working properly either.
Help!! 

Check to make sure radiator is full and overflow is filled to proper height.
Sometimes after flushing, you'll have air in system and when system cools it
will suck all the coolant from overflow. If there's not enough coolant then
there will still be air in radiator.
If full, remove radiator cap, start engine and let idle until engine comes
up to operating temperature. You should be able to see coolant start to flow
in top of radiator. This means thermostat has opened.
If functional, install radiator cap and feel heater hoses at firewall. If
one is hot and the other is cold then you don't have flow through heater
core. This could be plugged core or defective control, depending on where
control is. If you can see control and hose or tubing is hot past it (on
heater core side) then core is plugged.
If core is plugged, remove both hoses and fit a garden hose as tight against
the return fitting as possible. (Return is the hose that was cold when other
hose was hot) Turn pressure on and hope trash comes out. If so, flush for a
while until clear then reverse flow. Repeat as necessary until clear and
good flow in both directions.

--
Hope This Helps,
davidj92