Heater problem

Check the level of coolantin your radiator!

If the heater core has coolant in it, you get hot air as the fan blows thru it (while it is being slung in there, or is full as it should be)

If you are at idle, low on radiator juice, the heater core may be the part of the system lacking fluid, hard to extract heat from an empty heater core.

Your owner's manual usually prescribes checking your oil and coolant levels weekly (you or your agent, not Ole Fred at Sooper Dooper Lube in three months), so that you might detect any abnormality/ fluid loss before things get worse. Many people let this prescription sort of fall by the wayside. Many times it is too late when something shells out and they discover it was a simple fluid check, something cheap/ simple/ just a minute or two might have saved them thousands of dollars if they had just taken the time.

Many times, this is why you see old vehicles still "getting' it" on the road.

Mine are forty and seventy years old.

Keep us posted on how it goes.

The Medic

While engine is running check both heater hoses for heat, temperature set to high, low fluid level or partially clogged heater core.

I would lean towards a restricted heater core if the coolant is full.