I have an 85 22r and the heater is not working. I have replaced the thermostat, checked the fuses. The fan blows air but its cold. The hot cold register is not working. It reads cold even after an hour of driving.
Any help would be appreciated.
Thanks.

 

Did you test the new t-stat prior to installing it? How? Pot of hot water on the stove and a thermometer. Heat up the water and see what temp the t-stat opens and if it fully opens. Otherwise, trapped air in the cooling system. Run with rad. cap off with the front end higher. Any gurgling sounds behind the dash with the heater on and engine revved? And if the heater control cable actually attached to the valve on the firewall?

 

did it ever work? did it just quick working all of the sudden or do you know? probably a dirty/clogged heater core is my guess. You can unplug the hoses that go to the heater core and use some pressurized water and blast it through the heater core to unclogg it or clean it out so it transfers the heat. Also check that valve that allows the coolant to pass into the heater core. This could not be working also.

 

Check the heater valve under the hood, they can rust shut and stop working, if its bad upgrade to one from an 89 truck/4Runner, they use a newer design that will not rust like the original, i have one on my 86 4Runner and it works good.

 

Where would you get an upgrade and what would you ask for? I believe this is my problem with my 84 4runner.