Why does the air conditioner work in my 1998 Ford Explorer but not the heater. No heat comes out at all when heat is turned on.
7 Answers
CamaroCollector answered 8 years ago
Blend door actuator may have failed
That's a very good call Camaro collector, flush heater core / refill / and retest, also check heater control valve for opening and closing under hood on heater hoses passenger side close to firewall, make sure it switches when vacuum is applied
There is probably a vacuum canister somewhere, probably under the hood, which maintains vacuum when accelerating. There is usually a valve on it which can go bad resulting in the problem you are having.
The heater control valve has a vacuum diaphragm to open water passage to the heater- core
Just for information; he wanted to know why A/C worked and not heat. It is like apples and oranges... two separate, individual systems and not connected except for the dash controls. You can't take 1/2 of an apple and orange and join them... doesn't work
