MIDNIGHT RIDER
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My truck, 1985 model, factory A/C.
Located under the hood, right corner, just in front of the fire-wall and behind the blower housing, there is a vacuum actuator that operates a pivoting rod which I assume opens and closes a door.
If the fire-wall was a line running straight through 12-o'clock and 6-o'clock, with the right end being 6- and the left end being 12-, in all positions EXCEPT Max A/C, the operating-arm of this pivot is at about the 1:15 position and the operating plunger of the vacuum gizmo is extended.
Placing the selector in Max A/C causes the plunger to retract into the vacuum gizmo about 1/4-inch and places the arm at about 2-o'clock.
Does this amount of travel seem about right ??
What is the function of this door ??
On the control panel, the top control obviously works a cable that controls a door that opens more or less to adjust between HOT and COLD.
The lower control selects from left to right, in this order, OFF, MAX-A/C, NORM-A/C, VENT, FLOOR, MIX, and DEFROST.
If my understanding is correct, MAX-A/C is re-circulating the inside air through the evaporator, right ??
NORM-A/C is bring outside air across the evaporator and into the cab, right ??
I figure VENT is outside air.
What about FLOOR, MIX, and DEFROST; are they outside or inside air ??
Thanks.
Located under the hood, right corner, just in front of the fire-wall and behind the blower housing, there is a vacuum actuator that operates a pivoting rod which I assume opens and closes a door.
If the fire-wall was a line running straight through 12-o'clock and 6-o'clock, with the right end being 6- and the left end being 12-, in all positions EXCEPT Max A/C, the operating-arm of this pivot is at about the 1:15 position and the operating plunger of the vacuum gizmo is extended.
Placing the selector in Max A/C causes the plunger to retract into the vacuum gizmo about 1/4-inch and places the arm at about 2-o'clock.
Does this amount of travel seem about right ??
What is the function of this door ??
On the control panel, the top control obviously works a cable that controls a door that opens more or less to adjust between HOT and COLD.
The lower control selects from left to right, in this order, OFF, MAX-A/C, NORM-A/C, VENT, FLOOR, MIX, and DEFROST.
If my understanding is correct, MAX-A/C is re-circulating the inside air through the evaporator, right ??
NORM-A/C is bring outside air across the evaporator and into the cab, right ??
I figure VENT is outside air.
What about FLOOR, MIX, and DEFROST; are they outside or inside air ??
Thanks.