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66-96 Ford Broncos - Early & Full Size

Venting stuck no defrost/floor

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Hello all I hope you can help me. I picked up a 1985 bronco and the cable that shifts between the floor,vent,and defrost is missing or hidden to where I cant find it. Any help with pics where it runs to would be terrific. 

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Yo Blair,


The floor door is operated by a vacuum "motor". See attached HVAC vacuum diagram that includes hose colors.  The only cable operated door is the TEMPERATURE  Blend door.20191106_074946.thumb.jpg.89fdeaa8cd3a1eb201708a2acbb530e4.jpg Look for an abused black/yellow hose, begin behind instrument panel HVAC Controls to Floor/Defrost Vacuum Motor to Floor/Defrost Door.  I marked these with sloppy arrows  due to a bent index finger

Overview in 80-86; "Off - Vacuum is applied to Outside Recirc Door Vac Motor, closing that door to outside Air.

Normal A/C - Outside-Recirc Door is open to outside air. The panel door directs air to the instr panel registers.

The Temperature Control Lever moves a cable connected to Temp Blend Door that mixes heated & un-heated air. In Defrost Mode - No vacuum to any vacuum "motor" (cannisters looking things), air Flows to Defroster outlets (& air compr clutch is engergized).

Vent - Outside Recirc Door is open to outside air, as in Normal A/C. Vacuum is applied to the Panel Door Vacuum Motor, letting air flow only to the instr panel registers. In the same way, the defroster outlets are closed by the Floor/Defrost Vacuum Motor.

Floor - The Outside-Recirc Door20191106_074946.thumb.jpg.89fdeaa8cd3a1eb201708a2acbb530e4.jpg is Open to outside air. With No Vacuum at the Panel Door Vacuum Motor. The Panel Door directs air to the floor outlets.

Mix - Vacuum is applied only to Port A of the Floor/Defrost Vacuum Motor positioning the Floor/Defrost Door at mid-position. Air Flow is split between the floor & windshield. There is no vac at the Panel Door Vacuum" by me

Just in case;

See this Door Locations pic in 80-86 w/Dash dropped; "...After lowering the column, removing the big Aluminum casting, unbolting the 2 large connectors under the brake booster & releasing them from the firewall, the 3 connectors in the R kick, & the green ground screw, there are four 7mm (T15) screws along the w/s, an 8mm (5/16") at the R end, and two 8mm screws at the brace bars above the tunnel, and the dash flops onto the floor. Then the vacuum lines, HVAC cables, & antenna cable can be released, allowing the dash to come out..."
Source: by Steve

Floor Panel Door Location & Removal in an 86; "...I think the easiest way to fix it would be to go in through the heater core (behind the glove compartment)and on the left should be the panel door. Replace the panel door ..."
Source: by rust bucket 86 at Ford Bronco Zone Forums

Here are:

1985 Bronco Dealer Brochure via Gary @ 1985 Bronco - Gary's Garagemahal (the Bullnose bible)

1985 Electrical & Vacuum Troubleshooting Manual (partial) via Gary @
1985 EVTM - Gary's Garagemahal (the Bullnose bible)

1985 Bronco/F Series Specifications by Gary @ http://www.garysgaragemahal.com/axle-ratios.htm

1985-1986 Fuel System Adjustments by Gary @ 1985-1986 Fuel System Adjustments - Gary's Garagemahal (the Bullnose bible)

80-86 Bronco Differences by Gary @ 1980 - 86 Ford Trucks - Gary's Garagemahal (the Bullnose bible)

Fasteners & Illustrations by Gary @ Ford 1980-86 Pickup Fasteners - Gary's Garagemahal (the Bullnose bible)



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