HEAT/AC issue
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New User
Joined: Sep 2007
Posts: 5
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From: Manchester NH
HEAT/AC issue
Hello all,
This is my first post as I've just joined the forum. I recently purchased a 99 f-350 crew cab. I know I made a stupid mistake this but I never checked to see if the AC worked or the heater worked.
My questions are...
Can someone point me in the right direction to start diagnosing this? Is this a common problem? Is it an easy fix?
I can live without the AC but winters coming and I live in NH so heat is mandatory.
I will also be picking up a chilton's manual tonight.
Thanks for any help that can be provided.
This is my first post as I've just joined the forum. I recently purchased a 99 f-350 crew cab. I know I made a stupid mistake this but I never checked to see if the AC worked or the heater worked.
My questions are...
Can someone point me in the right direction to start diagnosing this? Is this a common problem? Is it an easy fix?
I can live without the AC but winters coming and I live in NH so heat is mandatory.
I will also be picking up a chilton's manual tonight.
Thanks for any help that can be provided.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
Check the heater hoses to ensure there isn't a valve in-line to shut off hot water flowing to the box.
When you switch from heat to defrost, do you hear a faint "thunk" in a second or so? That would be the position of the blend door changing. If not, start looking at the vacuum lines.
We'll need to know what engine you have, as if you have a diesel, the vacuum is from a different source.
We'll need to know if it's a four-wheel-drive, too, as the vacuum-operated hubs are prone to leaking, preventing vacuum from getting to the heater box.
Do you have flow out of the defroster vents only? That's a sure sign of vacuum loss.
There's a start for you.
Pop
When you switch from heat to defrost, do you hear a faint "thunk" in a second or so? That would be the position of the blend door changing. If not, start looking at the vacuum lines.
We'll need to know what engine you have, as if you have a diesel, the vacuum is from a different source.
We'll need to know if it's a four-wheel-drive, too, as the vacuum-operated hubs are prone to leaking, preventing vacuum from getting to the heater box.
Do you have flow out of the defroster vents only? That's a sure sign of vacuum loss.
There's a start for you.
Pop
Thread Starter
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New User
Joined: Sep 2007
Posts: 5
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From: Manchester NH
vacuum lines
Thanks
It is a V10, 4x4, and yes there is plenty of air movement from the defroster. I will take a look at the vacuum lines as soon as I can.
Now that you bring that up do the manual locking hubs also have a vacuum line conenected to them?
It is a V10, 4x4, and yes there is plenty of air movement from the defroster. I will take a look at the vacuum lines as soon as I can.
Now that you bring that up do the manual locking hubs also have a vacuum line conenected to them?
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Of the next Riffraff East
Joined: Oct 2004
Posts: 8,679
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From: Concord NC
I think what Pop is asking, do you get air out of the defrost as well as floor vents when you change the switch?
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Of the next Riffraff East
Joined: Oct 2004
Posts: 8,679
Likes: 2
From: Concord NC
If the switch is moving the air flow from the defroster to the floor vent and the fan is running then you need to look elsewhere. The heat flows through the coil unless like Pop suggested, there has been a valve installed to turn the flow off during warmer season. If you don't have any cooling, sounds like you compressor is not working or you are out of freon. Look and see if compressor is working. Clutch may not be engaging correctly.