Knowledgeable Ford person question?

Hi,

I have taken apart some heater boxes, and found that sometimes (like in this case) the hot water goes through the heater core all the time, and you adjust the 'hot - cooler' control to swing a damper from fully open to just the cold air from the cooling coil, or to all the air going through the hot water coil, or something in between.

I have found that a ball valve inline with the heater core water lines is handy to keep the air cooler coming out of the A/C vents! The 'insulation' between the hot water coil and cool airstream is only about 1/8" thick plastic door!

Fred.

Gdetrailer wrote:

2112 wrote:

Bird Freak wrote:
Check under your hood and see if the vacuum tube has come off the heater control valve. If it will not shut the hot water off it will blow hot. Mine did that.

My '97 did this. The vacuum line was brittle and broke. It fails hot.

OP has a 2000, sometime in the early 2000 models Ford OMITTED the vacuum shutoff valve. My 2003 F250 DOES NOT HAVE any hot water shutoff so the core is always hot.

The OP has one of two known issues, the easy one to fix is the A/C compressor clutch, the clutch material has worn down and is not engaging the compressor.. And YES, when the compressor is not engaging you WILL get HOT air..

To fix that you pull the compressor clutch and remove a shim to re-establish the correct air gap for the clutch.

The worst case issue is the "blend" door motor which blends the hot and cool air has failed.. Changing the blend door motor is a real bear from what I understand..

Do a search for a/c compressor clutch repair, should be able to find that info and do a search for Ford blend door motor should be able to find details on that repair..

I know my 04 has a valve under the hood on the evaporator case.

2112 wrote:

Bird Freak wrote:
Check under your hood and see if the vacuum tube has come off the heater control valve. If it will not shut the hot water off it will blow hot. Mine did that.

My '97 did this. The vacuum line was brittle and broke. It fails hot.

OP has a 2000, sometime in the early 2000 models Ford OMITTED the vacuum shutoff valve. My 2003 F250 DOES NOT HAVE any hot water shutoff so the core is always hot.

The OP has one of two known issues, the easy one to fix is the A/C compressor clutch, the clutch material has worn down and is not engaging the compressor.. And YES, when the compressor is not engaging you WILL get HOT air..

To fix that you pull the compressor clutch and remove a shim to re-establish the correct air gap for the clutch.

The worst case issue is the "blend" door motor which blends the hot and cool air has failed.. Changing the blend door motor is a real bear from what I understand..

Do a search for a/c compressor clutch repair, should be able to find that info and do a search for Ford blend door motor should be able to find details on that repair..

colliehauler wrote:
On my heater control the temp control blows hot even when you turn it to cool on the temp control.

The truck is a 2000 F-250 Superduty.

I did not see a control device on the heater hose, so I assume it is internal by the heater core.

Any ideas?

If it is a diesel like mine, there is no heater control valve.
The fresh air comes from the vents at the bottom of the windshield.
Try this thread... AC mod

Bird Freak wrote:
Check under your hood and see if the vacuum tube has come off the heater control valve. If it will not shut the hot water off it will blow hot. Mine did that.

My '97 did this. The vacuum line was brittle and broke. It fails hot.

Vacuum switch and under hood heat have both happened to me

Check under your hood and see if the vacuum tube has come of the heater control valve. If it will not shut the hot water off it will blow hot. Mine did that.

colliehauler wrote:
On my heater control the temp control blows hot even when you turn it to cool on the temp control.

The truck is a 2000 F-250 Superduty.

I did not see a control device on the heater hose, so I assume it is internal by the heater core.

Any ideas?

Unless you turn on the AC. the vents get their air from under the hood area. If it is hot there. The air will be hot / warm coming out. You can turn on the AC for a few min to cool the hoses

If the truck has been sitting with the dash in the sun it will do that for a while until the vent plumbing cools off. Kind of annoying. If it still does that after several minutes then it probably a control damper.

I had a 2003 Explorer that did that and it was a part inside the dash that moved the damper from hot to cold it was plastic gears and they wore out my guess it could be the same issue it was a fairly easy DIY