answersLogoWhite

0


Best Answer

vacuum controlled doors ...vacuum leak or a pen or pencil down the vents....look at some pics Everyone should have a manual for their vehicle, and the library should have a professional shop manual available in the reference section(make copies of the right sections) read up and fix it like a PRO! :) good luck

User Avatar

Wiki User

17y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

13y ago

it sounds like the blend door actuator has gone bad it could be vaccum operated or by cables either way i would check to see if either one of the vaccum lines for the actuator has come loose or if one of the cables has slipped off there by leaving the blend door in defrost only

reply to this answer: I have a 2000 Jeep Grand Cherokee and have the same problem , I took the info that the dealer said it was a vacuum problem. I found a vacuum line on the passenger side running along the top of the firewall and then down, there is also what looks like a ground strap from the firewall to the engine right above the valve cover , well this ground strap was touching the vacuum line and obviously this ground strap will get hot because it's attached to the engine. The ground strap melted the vacuum line , I cut out the melted section and attached the two ends with a coupler. Problem solved !

Most likely the vacuum line coming off the right side of the intake manifold just below the throttle body. Look for a small line dangling and reconnect...easy!

This answer is:
User Avatar

User Avatar

Wiki User

14y ago

Bad blend door actuators or plugged up doors from debris etc. To fix this you will need to remove the dash completely. Stupid engineering....

Thanks for the info. do you know where I can get the heater housing unit ? that is what someone said I needed to replace.

I've never heard of it called a heater housing unit. This other person is probably referring to the condensor box where the heater core and air conditioner A-frame is located. The fan is attached to this box. The box also serves to remove humidity from the inside air. If you get air blowing out of some vents and not others you have a blend actuator door problem. These are little doors that open and close in the duct work behind the dash that direct air flow to the floor or defrost etc. These doors get jammed with peices of styrofoam from the lining of the condensor box as well as other debris and are sometimes accessible without totally removing the dash. If, when you turn on the fan switch, you don't hear the air coming out anywhere then you likely have a bad fan or switch or perhaps a blown fuse. The proper fuse is located behind a small plastic door on the side of the dash when you open the passenger door. It should be fuse number 17, a brown plug in fuse rated at 7.5 amps. If the fuse is blown and then blows after you replace it then you have an electrical problem that needs to be addressed. I would try to replace the fuse and if that doesn't work take it to a reputable dealer or heating/AC guy for an estimate. Removing the dash to get at parts is VERY expensive due to the time it takes and therefore the labor costs. Hope this helps.

This answer is:
User Avatar

User Avatar

Wiki User

10y ago

Either you need to pen your vents or there is some vent obstruction.

This answer is:
User Avatar

User Avatar

Wiki User

11y ago

the mode door inside the hvac unit has most likely broken causing to to default to defrost. sometime the actuator is at fault, wither way the dash has to come out

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why does the air conditioning in your 1997 Jeep Cheerokee blow cold but randomly switches from blowing through the vents and the defroster?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Micro switches are used for what purpose?

Micro switches are small snap-action switches generally used in some type of electronic circuit for some type of repetitive motion. In an air conditioning unit, a micro switch might send a signal to turn the compressor on or off when a room reaches a certain temperature.


Does thermostate control double radiator fans in Honda cr-v?

One of the fans operates independently of the air conditioning system. The other fan will only operate if the air conditioning system is turned on and the engine needs extra cooling to exhaust the heat transferred to the engine coolant by the operation of the A/C. They both are tirggered into operation by thermostatic switches but not the same switches. They are independent of one another. CAUTION: Do not confuse these thermostatic switches with the actual cooling system thermostat contained in the engine block that controls the flow of the coolant.


Why do your iPod not working?

It depends on why it's not working. If the iPod just randomly died and won't turn on, the best thing to do is to hold the home and on/off button at the same time untill it switches on.


Does the air conditioning system have to be full of freon for the compressor to engage?

Yes, with both freon and oil for it to operate correctly and engage unless someone has bypassed the pressure switches or relays..........


Why is Mercury used in light switches?

Mercury is used in switches because it is a liquid metal, conducts electricity, and is very stable. Switches made from mercury are also called "Silent Switches", since the switching occurs when the mercury makes the connection between the contacts, instead of a mechanical switch. The mercury is usually contained in a small glass vial within the switch. It is also commonly found in home thermostats, used to control heating and/or air conditioning systems.


What are the main parts of auto air conditioning?

The main parts of any mobile or stationary air conditioning system are the compressor, hoses/lines, expansion valve, evaporator coil, condenser coil and fans to move air through both coils. You also have various pressure, temperature, and on/off switches that controls the system. An air conditioning system is a fairly simple system.


What part of an HVAC system switches the unit from air conditioning to heat and heat to air condtioning?

In HVAC (heating, ventilating, air conditioner) A thermostatic switches the unit from cooling to heat. In Heat pump unit it's the four-way valve or reverse valve. However, the thermostatic still controls it.


What is the black switch next to the transmission power switch on the console in a 1989 jeep Cherokee?

It should be for the rear wiper or rear defroster. I have a 1992 (no power switch), but on the left side of my column are the fog light and rear defrost switches, and on the right is the rear wiper switch.


How you get through the electric fence in Vermilion city gym in Pokemon fire red?

there are two switches hidden randomly in the trash cans u MUST push both at the same time cause there are 2 fences.


What kinds of switches are available from Carling Technologies?

Carling Technologies produces rocker switches, toggle switches, push button switches, rotary switches and mini and submini switches. Each of these types of switches are offered in a variety of sizes.


What is the function of the blendor acuator?

The blend door actuator's function is to blend the outside air/heat or outside air/ air cond to get the desired temperature out of the unit. It also switches between heat and air conditioning modes.


Rear air conditioning fan not coming on tried two used switches but still no power Power is there because you can jump it from one wire to another and make blower come on what are solutions?

Check for any relay and or blown fuses