Ac nt working an i do ac work for a living an cant figure out
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From: Ca
Ac nt working an i do ac work for a living an cant figure out
Ford ranger 2009 4 cCylinder 2.3 liter stick shift .problem iam having ac works great idling but soon as i start driving fan starts blowing air out dash cuts out until i bring bac to idle yes i understand it can do that if i am on the gas hard but iam barley giving it gas
Welcome to the forum
So this is not an AC issue it is a blower/fan or Vent direction issue?
The Vent direction is controlled by Vacuum, Default(no vacuum) is the Defrost vent, so is the blower air being redirect to Defrost vent?
If so then it is a vacuum issue, which changes with throttle position.
The blower/fan gets 12volts with key on, the Cab panel selects the Ground path for the blower motor, which shouldn't change with RPM
The Blend door controls air flow thru the heater core, temp control **** sets Blend door position, it is electric, in COLD setting no air goes thru heater core, in HOT setting all air goes thru heater core.
So Blend door can not cut off air flow, it just redirects it thru heater core or not.
Vent direction, i.e. panel, floor or defrost, is vacuum operated
The Vacuum comes from the Vacuum reservoir in the engine bay, usually located in the front of engine bay, passenger side, down low, looks like a black plastic ball.
There will be a black hard plastic vacuum hose from there to the Firewall on passenger side, there ids also a Grey plastic vacuum line on the firewall that goes to the Heater hose valve in the engine bay
The black vacuum line can melt or crack near exhaust system, or any where really
The Vacuum reservoir can also crack and leak,
The Vacuum reservoir is connected to engine's intake vacuum with a check valve, much like power brake booster, so it holds lowest vacuum of engine, which is at idle, -21" of vacuum.
Vacuum is not "used up", but can leak away.
If you do the "straw trick", i.e. dip a straw in a liquid and put your finger over the end, then lift up the straw, the liquid stays in the straw, vacuum pressure is holding it in the straw, and it will stay there until you move your finger, it is not "used up" over time, it will stay forever, unless vacuum leaks out, or outside air pressure leaks in to be correct, lol.
So do the test, is air being redirected to Defrost Vents?
If so its a Vacuum issue
If vacuum at vents is minimal then any opening of the throttle would cause redirect to Defrost vents
So this is not an AC issue it is a blower/fan or Vent direction issue?
The Vent direction is controlled by Vacuum, Default(no vacuum) is the Defrost vent, so is the blower air being redirect to Defrost vent?
If so then it is a vacuum issue, which changes with throttle position.
The blower/fan gets 12volts with key on, the Cab panel selects the Ground path for the blower motor, which shouldn't change with RPM
The Blend door controls air flow thru the heater core, temp control **** sets Blend door position, it is electric, in COLD setting no air goes thru heater core, in HOT setting all air goes thru heater core.
So Blend door can not cut off air flow, it just redirects it thru heater core or not.
Vent direction, i.e. panel, floor or defrost, is vacuum operated
The Vacuum comes from the Vacuum reservoir in the engine bay, usually located in the front of engine bay, passenger side, down low, looks like a black plastic ball.
There will be a black hard plastic vacuum hose from there to the Firewall on passenger side, there ids also a Grey plastic vacuum line on the firewall that goes to the Heater hose valve in the engine bay
The black vacuum line can melt or crack near exhaust system, or any where really
The Vacuum reservoir can also crack and leak,
The Vacuum reservoir is connected to engine's intake vacuum with a check valve, much like power brake booster, so it holds lowest vacuum of engine, which is at idle, -21" of vacuum.
Vacuum is not "used up", but can leak away.
If you do the "straw trick", i.e. dip a straw in a liquid and put your finger over the end, then lift up the straw, the liquid stays in the straw, vacuum pressure is holding it in the straw, and it will stay there until you move your finger, it is not "used up" over time, it will stay forever, unless vacuum leaks out, or outside air pressure leaks in to be correct, lol.
So do the test, is air being redirected to Defrost Vents?
If so its a Vacuum issue
If vacuum at vents is minimal then any opening of the throttle would cause redirect to Defrost vents
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Joined: Sep 2017
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From: Elizabethtown
The guy above is correct, when your vaccum ball goes out your hvac controls stop working under load when there is no vaccum.
AND
if your operating on MAXAC mode there is a hose that closes the heater core, if you don't have vaccum it won't close and you'll get ac mixed with heat like your describing
AND
if your operating on MAXAC mode there is a hose that closes the heater core, if you don't have vaccum it won't close and you'll get ac mixed with heat like your describing
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