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Discussion Starter #1
i've flushed the system, my hoses are getting hot, i have new tstat & water pump. When i turn the heat on, all i get is room temp air or cooler. I pulled the core out and flushed through it everything was clear coming out no clogs. any ideas?

ps. my A/C works great if that helps

thanks guys
 

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ahhhh..... crap!!!
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Probably a vacuum leak
 

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Discussion Starter #3
how might i go checking if this is it?
 

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Discussion Starter #4
i checked the line going ot the water pump its fine, the one going to the intake looks fine also as far as i can see it, bu ti'm not sure where the vacuum comes in. I don't see a valve intersecting anywhere on the lines
 

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There is a cable that runs from the cool/heat switch to a door that moves from the heater core, to the AC. Is that cable moving, and if it is, is it moving the door.

The cable should connect to the door right above the heater core box.
 
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Discussion Starter #6
ok i took out the panel with the dials on it. the cable is moving and i can hear the door moving on the blower beside the heater core
 

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Discussion Starter #7
Correction, i took the panel off AGAIN of the heater core to see if it moves the door, it don't think it does, how far back {(from inside the cab) is the door? i stuck my arm up as far as i could and nothing was turning, and i didn't hear anything this time.
 

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yo;

Blend Door Location in a 94; 80-96 similar; "...Probably the temp blend door is loose & flopping around on its own. The easiest way to see it is to fully lower the glove box, pull the ~8 screws from the heater core cover, & look inside to the L (driver's side). You'll see the cable & control lever (in top L of 2nd pic) as soon as you fold the glovebox down, so inspect it first. The 3rd shows the whole cover - it's the large section in the top center with tiny white numbers inked near its bottom edge. The cables are visible, too...."

Underdash Ventilation Duct '80-86 - '87-96 similar
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Source: by Steve83 (Steve, That dirty old truck) at FSB


Blend Door Control Cable pic in a 92

Source: by 2bet at SuperMotors.net

Climate Control Assembly: The heater is a blend air type that receives its outside air supply from the cowl inlet. The heater control (18549) is located in the instrument panel (04320) to the right of the steering column. It includes the function control knob, temperature control knob and heater blower motor switch (18578). The heater blower housing assembly includes: Blower motor (18527), Heater blower motor switch resistor (18591), A/C damper inlet door (19C802), Vacuum control motor (18A318) to operate A/C damper inlet door, Electrical harness. The heater blower housing is installed on the engine compartment side of the dash panel. Electrical wire receptacles for the blower motor and heater blower motor switch resistor are provided on the heater plenum chamber case (18A484) and a vacuum connection is provided on each vacuum control motor. heater air plenum chamber (18471), on the passenger compartment side of the dash panel attaches to the heater plenum chamber case through the panel with an air passage between the assemblies provided through an opening in the panel. heater air plenum chamber includes the following components: Heater core (18476), Temperature blend door, Floor/panel door, Floor/defrost door, Vacuum control motors and vacuum hose harness (19C827). The vacuum control motors and their vacuum lines operate the floor/defrost and floor/panel doors. The temperature blend door is operated mechanically by a A/C temperature cable (19988) attached to the temperature control knob in the heater control. The function control knob is used to select the functional setting of the heater system. The settings are: VENT, FLOOR, OFF, MIX and DEFROST. Power is supplied to the blower motor when the function knob is in any position except OFF. Airflow Control: Outside air is supplied to the system through the cowl top grille. This air supply enters the heater plenum chamber case where the blower motor directs some or all air through or around the heater core depending upon the setting of the temperature control knob. Airflow through the heater air plenum chamber is determined by the setting of the function selector knob in the heater control. The outlets through which air may be distributed into the passenger compartment are shown in the following illustration. Temperature Control: Depending upon its position, the temperature blend door in the heater air plenum chamber directs a given amount of air through the heater core to provide a desired amount of heat. If the amount of air directed by the blend door through the heater core is reduced, less heat will be directed into the passenger compartment. Conversely, a fully open blend door, in response to a fully WARM setting of the temperature control knob, will provide maximum heat into the passenger compartment.
by Ford


System Airflow
The following airflow diagrams illustrate the path airflow takes in response to each functional setting of the control knob. The position of the function control knob in the heater control (18549) determines which of the damper doors are open, partially open, or closed.

OFF
In the OFF position, the OUTSIDE AIR door is closed to block the entry of air from the cowl into the heater air plenum chamber (18471).

VENT
NOTE: The temperature door can be set to full cool, full warm or anywhere in between. The function control knob does not affect the temperature blend door; this is governed by the temperature control knob.
In the VENT position, the OUTSIDE AIR door is open and the PANEL/DEFROST door is open. The airflow is directed to the registers in the instrument panel (04320).

FLOOR
NOTE: The temperature door can be set to full cool, full warm or anywhere in between. The function control knob does not affect the temperature blend door; this is governed by the temperature control knob.
In the FLOOR position, the OUTSIDE AIR door is open. Airflow is directed through the TEMPERATURE BLEND door opening, through the heater core (18476), past the closed FLOOR/PANEL door and out through the open FLOOR/DEFROST door to the heater outlet floor duct (18C433). There is also an air bleed past the closed FLOOR/DEFROST door to the windshield defroster openings.

MIX
NOTE: The temperature door can be set to full cool, full warm or anywhere in between. The function control knob does not affect the temperature blend door; this is governed by the temperature control knob.
In the MIX position, the airflow follows the same path as described for FLOOR position, except the FLOOR/DEFROST door is in the mid-position with an equal amount of air flowing to the heater outlet floor duct and the windshield defroster nozzle.

DEFROST
NOTE: The temperature door can be set to full cool, full warm or anywhere in between. The function control knob does not affect the temperature blend door; this is governed by the temperature control knob.
In the DEFROST position, the FLOOR/DEFROST door is fully open to the windshield defroster hose nozzle (18490) with a bleed amount going past the closed door to the heater outlet floor duct.

Airflow Diagrams (SEE attached diagram at end of tis reply)


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TSB 96-13-7 AIR CONDITIONING/HEATER - LOW OR NO HEAT/AIR CONDITIONING - HIGH EFFORT TO TURN TEMPERATURE CONTROL KNOB - POOR TEMPERATURE MODULATION - LOW OR NO HEAT/COOLING - VEHICLES BUILT THROUGH 2/27/95

Publication Date: JUNE 17, 1996
LIGHT TRUCK: 1992-1995 BRONCO, F-150-350 SERIES, F-47

ISSUE: The temperature control knob may be difficult to turn on some vehicles. There may also be a low or no heat/cooling condition accompanied by poor temperature modulation. This may be caused by the single cable temperature door operating system being used.

ACTION: Replace the A/C Temperature Control Cable Assembly with a new pull/pull cable design. The new design cable will provide improved control of the temperature door. Refer to the following Diagnostic and Replacement Procedures for details.
DIAGNOSTIC PROCEDURE
1. If the vehicle exhibits high effort turning the temperature control knob or poor temperature modulation, a new cable must be installed. Refer to the Replacement Procedure listed in this article. For a low or no heat/cooling concern, continue on with the Diagnostic Procedure.
2. Check vehicle's coolant for the correct level, concentration and operating temperature with the thermostat open. If a concern is found in one (1) of these areas, refer to the appropriate Service Manual for repair procedures. The repairs must be done before proceeding.
3. Verify proper A/C system charge and operation. Repair as necessary.
4. If the concern still exists, perform the Cable Adjustment procedure listed in the appropriate F-Series/Bronco Service Manual, Section 12.
5. If the concern still exists, replace the temperature door cable. Refer to the following Replacement Procedure for details.

REPLACEMENT PROCEDURE
REMOVAL
1. Remove glove compartment and module assembly, if present.
2. Detach cable from plenum using Tool D91T-18532-A. Remove and discard cable.
3. At the cable bracket on the plenum heater core cover, cut away the bracket using a hacksaw blade or similar tool.
4. Remove the 5/16" headed screw from the top of the cam. Discard the cam and screw with spring clip.
5. At cam post, add post extension and secure with the new screw, torquing the screw to 1.7 N-m (15 lb-in).
6. Remove the upper left screw securing the plenum heater core cover and install the A/C plenum chamber support bracket between the ribs to the right side of the bracket which was cut off. Make sure the hole from the previously removed screw is lined up with the hole in the plenum chamber support bracket.

INSTALLATION
1. At the plenum chamber, move the temperature door arm to the "full warm" position (counterclockwise) and be sure it remains there throughout the installation procedure.
2. At the small end of the cable (control head), remove the temperature control bracket from the cable by releasing the three (3) snaps using Tool T94P-18532-A or a thin blade screwdriver to allow the cable to be pushed back through the instrument panel toward the control head.
3. Be sure the new pull/pull cable is in the "full warm" position. Check the molded-in arrow at the control head portion of the cable. Normally the cable is shipped in the "full warm" position.
4. At the plenum, position the cam end of the cable over the post. Make sure the temperature door arm can move into the slot of the cam and push down until the cam is engaged on the post. An audible click can be heard. If it is necessary to remove the cam cable head, use moderate finger pressure on the plastic tab at the top of the cam cable head, moving it back so the cam may be pulled out off the post.
5. Place the twin cables in the center slots of the A/C plenum chamber support bracket. If adjustment is needed later, the cables can be moved to the other adjacent slots.
6. Route new cable through the instrument panel following the same path as the old cable.
7. Check the new temperature control bracket to be sure it is in the "full warm" position. The tab should be in the slot in the bracket.
8. Push the temperature control bracket onto the control assembly and turn it to catch under the retaining tab. Secure with the new screw previously saved.
9. Place the knob on the temperature control.
10. Push the cable head onto the temperature control bracket (make sure gear pilot centering hole is lined up correctly) until the three (3) lock into position (you should hear a click of three (3) tabs).
11. Install temperature control assembly in instrument panel.
12. Swiftly rotate temperature control knob to each extreme (cool-warm) and listen for the sound of the temperature door closing in both directions. If no audible close is heard, move the cable into different slots at the A/C plenum chamber support bracket covered in Step 4 of the Installation Procedure until there is an audible close in each direction.
13. Bring vehicle to operating temperature and verify proper heating and cooling by measuring the temperature of the discharge air at the outlets.
14. At A/C plenum chamber support bracket, secure cable to bracket with a tie strap to keep cable in place.

Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

The Temperature Control Cable Kit (F5TZ-19988-CA) consists of:
· One (1) Temperature Control Cable
· One (1) Temperature Control Bracket
· One (1) Plenum Support Bracket
· One (1) Post Extension
· One (1) Screw
· One (1) Tie Strap
· One (1) Instruction Sheet (I.S. #6630A)
PART NUMBER: Temperature Control Cable Kit
PART NAME: F5TZ-19988-CA
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION: 961307A
DESCRIPTION: Install Pull/Pull Cable Retrofit Kit
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Lack of Heat, Temperature Blend Door Cam Spring Does Not Blend Door to Seat Properly TSB 92-4-13 for Vehicles Built Prior to 11/11/91, 92 Bronco & F Series & F-47
Source: by Ford via Chilton
 

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yo,
One more.. I have more info in my site @ http://www.broncolinks.com/index.php?index=964


such as;
Blend Door (Temperature Control) Control Cable Replacement in a 96; "...Installation: "...Release the glove box to gain access to the retainer clips on the plenum end of the cables. Depress protruding retainer clip and pull upward to free from plenum. NOTE: Removal of the A/C temperature cable (19988) from the heater control (18549) is easiest if temperature control is removed from the heater control. Installation: NOTE: All replacement service parts are shipped in the full warm position and must remain in full warm to permit proper alignment during installation. Cables are serviced as a complete assembly only. Route A/C temperature cable in same manner as cable removed. Position temperature control knob in full warm. Install temperature control switch in heater control and position A/C temperature cable so that all three retaining tabs and the beveled gearing is properly aligned. Be sure all components are adjusted to the full warm position. Push A/C temperature cable onto temperature control switch until it is fully seated and all retaining clips are engaged. Install heater control. Working through glove box opening, position temperature blend door in the full warm position. Align A/C temperature cable to locating post, align cable assembly hardshell positioning tab with keyed area on the heater air plenum chamber (18471) and the temperature blend door actuator post aligned with the cam on the cable head. Push assembly onto plenum until retaining tab is engaged. Install retaining bracket. Rotate the temperature control knob and check for operation of the temperature blend door..."

Other than Blend Door Replacement in 92-96: "...The damper doors inside the heater air plenum chamber (18471) cannot be replaced. As a result, if there is a problem in the mix or the panel/defrost door, the heater air plenum chamber, including these doors, must be replaced. The heater air plenum chamber must also be replaced if there is damage to the mounting studs that cannot be repaired..."
 

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May have been mentioned but the valve for opening the heater core to allow coolant to flow is under hood passenger side. My vacuum line was rotted and causing all kind of problems. Fixed it and lots of stuff got better.
 

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oh boy, removing the dash... Any advice or pointers in getting the dash out? Pass. side is easy enough not to many screws and bolts but the drivers side seems to be attached evrywhere
 

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yo,
I have the Dash (Instrument Panel) Removal & Installation in a 96 from 1996 F-150, F-250, F-350, F-Super Duty and Bronco Workshop Manual by Ford in my site @ http://www.broncolinks.com/index.php?index=233
scroll down to...Dash Removal in a 96
 

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It's totally different from all prior years. I thought Spicy's profile said '86, but it's not there now... :rolleyes:
yo,
I thought that I saw it was a 96
Now is see it is a 91

I did have a headache, now it is worse.:banghead
 

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Thank you everyone for the advice, warming up a bit here so maybe i'll tackle that soon. But first i have to replace my core support and body mounts... sounds like a whole lotta fun, huh?
 

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You said you changed the tstat. Do not want to come off as insulting but have seen them put in upside down before. Probably not but it has happened. Again not questioning your mechanical abilities.
 

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You've got it easy! ;) Some of us have a little more work to do:
yo, Speakin' of work; Navy/DoD just sent me my 35 yr pin! a little late though:doh0715:
 
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