2002 heater issue

[american steel]

I have a 2002 xlt that blows hot air for about 10 seconds and then it goes to cool air. I would turn it off then wait 30 seconds and I would turn it on high hot air blows for a short time. this isn't my daily driver I decided I will restore this expedition. for the first time in 4 months i started the engine. just to see how every thing works.
i replaced the transistor or what ever its called and the fan speeds work fine.
the door is not making any kind of noises.

 

[stamp11127]

What are you turning on/off - engine or blower motor?

 

[american steel]

What are you turning on/off - engine or blower motor?

the blower motor

 

[JUST4FUN]

Sounds like the core is filled with rust needs to be power flushed

 

[american steel]

Sounds like the core is filled with rust needs to be power flushed

that's what I was thinking. if I get time this weekend ill do that

 

[stamp11127]

You can check the condition of the coolant in the surge tank. If you see any junk mixed in with the coolant you should perform a system flush first then disconnect the heater hoses and flush the core in both directions. This also applies to the rear core.
If you have the original style clamps you will need the removal tool in order to get them off the lines.

 

[american steel]

You can check the condition of the coolant in the surge tank. If you see any junk mixed in with the coolant you should perform a system flush first then disconnect the heater hoses and flush the core in both directions. This also applies to the rear core.
If you have the original style clamps you will need the removal tool in order to get them off the lines.

the coolant is pretty clean.

 

[stamp11127]

How do the walls of the tank look? Crap usually will stick to them.
Before tearing into the system, check the heater hoses once the engine is up to operating temperature. Both should be pretty hot to the touch.

 

[american steel]

How do the walls of the tank look? Crap usually will stick to them.
Before tearing into the system, check the heater hoses once the engine is up to operating temperature. Both should be pretty hot to the touch.

the tank is clean the coolant and the sides.
im headed to my shop now and ill turn the expedition on and see if the hoses I have a feeling its a heater core stuffed with rust/scale and trash.

 

[stamp11127]

There is a restrictor in one of the heater hoses. Usually when there is trash in the system it will also collect inside the hoses. You may want to remove the hoses from the engine first and inspect the inside. The quick connects on the heater core are just that. They can be a real pain to get off. Watch out for the two o-rings and spacer used on them. I replaced the o-rings with some from a hardware store.