No heat

[thejum57]

I'm getting no warm air from the truck. In the past, the heat was fine. I can change it from heat to defrost. When I change it from cold to hot there is no "noise" like it used to do like when a diverter door opened or shut. Also all hoses get hot except for this one by the heater

and the lower radiator hose. It has a new radiator, all new hoses. I ran water through the heater core...both ways, and it flowed freely. I don't see any vacuum lines that are broken. Maybe something behind the dash? Does anyone have suggestions? It's getting pretty cold here in MA. By the way, it's an 86, 2.5liter. Thanks, Jim :???:

[KYMJ]

The hose you're pointing at is the outlet. If it is not hot, I suspect the heater valve is shut closed.The one on my truck stays open at rest and closes with vacuum. Do you have vacuum on the line? What happens when you apply vacuum? I would look there first. You stated that the top hose is hot. Can you tell if there is a difference before and after the valve? Coolant level? You stated that the core is running freely. Can think of no other reason for both lines to not be hot. This comes after diagnosing my heat problems last week. Don't know if a 4.0 differs any.

[maddzz1]

Did you check the vacuum ball located in the front bumper, and check the vacuum lines going to it