answersLogoWhite

0


Best Answer

Check for vacuum leak--either under dash or in engine compartment Check for bad vacuum motors under dash Defrost is the default position for this system There is a vacuum resovoir located behind your battery , it is for this condition.

When you accel your engine doesn't produce vacuum due to the throttle plate being open so a resovoir is there to hold a vacuum reserve so that when there is low vacuum produced by the engine there will be reserve to hold the vacuum motor applied preventing the air from changing direction in your dash.

When there is no vacuum the direction is at the defrost vents if you have a broken hose or no vacuum your ac would blow out the defrost all the time

But since it happens when you accel it sounds like your vacuum resovoir is cracked thus not allowing it to hold a vacuum

User Avatar

Wiki User

16y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: 2002 ford expedition max ac only blows out thru defrost vents?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Why do i have a Burnt oil smell through defrost vents in a 2002 Sable?

FIND A PERSON WHO KNOWS A HOUSE CHECKER OR SOMTHING


2002 winsrtar lx ac started blowing only through defrost vents onlytried turn every know still only blows through defrost vent?

Check under the hood for a disconnected or damaged vacuum line. The controls are vacuum operated and if the vacuum supply is cut off the system defaults to defroster only.


I have a 2002 Ford Explorer that is get low air flow from the defrost vent when the defrost unit is selected. Most of the air flow is going to the floor vents. Is the blend valve bad?

Hi, It is not the blend door, that is for heat/cold changes. The mode door could be the problem, or stuck defrost door.


Why do you not have air flow from the dash vents on a 2002 Mercury Sable when the defrost and floor vents work fine?

Your most likely issue is a bad hvac control switch. On older cars, this was operated by vacumm pressure, but on a 2002, it is all electrical. It may be that you need to replace the whole control unit.


What should you look for when your 2002 Astro blows ac only at the bottom and top vents and not very strong?

Check for a broken vacuum line. The vacuum line controlling the doors on the heater/AC blower is a small hard plastic line. When it breaks it has little affect on the engine performance but the vents default to defrost for safety reasons. The few I replaced start at the front portion of TBI base. Your parts person can show you where it is and it isn't expensive.


Air not blowing through vents just floor and defrost on a 2002 jeep?

when it happened to mine, it was because the arm behind the dash that controls the internal vent doors slipped off


2002 Oldsmobile Alero only blows warm air when heater is on and only when its on defrost?

Could be,a stuck open thermostat,low on coolant,plugged heater core,faulty temp blend door actuator,


How do you fix the air conditioner on a 2002 Ford Windstar that switches from the panel to the defrost vents when the engine is under a load?

Sounds like you have a vacuum leak - -bad or loose hose or defective diaphragm in one of the vacuum motors


What would cause air to only blow from the defrost and floor vents and not blow out of the panel vents even when the switches are turned to the panel vents in a 2002 Ford Explorer?

Any of the following can cause this......... 1. Bad a/c - heater controller.. 2. Bad a/c - heater controller inside door operation.. 3. Bad, broken or cracked vacuum line/lines..


How many valves does the 2002 Ford Expedition have?

The 2002 Ford Expedition has 16 valves.


What size engine does the 2002 Ford Expedition have?

The 2002 Ford Expedition has a V8 engine.


When accelerating or engine under load of 2002 f-250 ac air from dash vents moves to defrosters then to floor while cruising it works fine any ideas?

you have a vaccumm leak defrost is the normal at rest vent setting