Well for some reason the climate control air only blows through the top vent up on the dash and won't blow through the normal vents no matter what setting its on.

Its like its on defrost all the time, anyone know what could possibly be wrong here?

 

vac. leak or possibly a bad switch.

 

pretty sure its not a vac leak or it would have a rough idle id assume

 

it's a vaccuum leak most likely. Check that little black ball underneath the airbox assembly on the passenger fender well, make sure there are no cracks, missing vaccuum lines, etc.

 

I have this same problem and was told to look behind the glove compartment... couldn't find anything...

So I should look under the passenger fender well for a black shaped ball? Does it look like the smog ball?

 

No vac to the system. without vacume the system "defaults" to deforst on the blend doors.

 

there are a group of colored hoses that come from the back of the HVAC head unit. check to make sure that one of those isn't cracked or off.

 

The vacumm ball is in the fenderwell on 4wd's and is hard to get to, its beside the airbox but inside the fender. On 2wd's the ball is below the alt and airbox in the engine compartment. If you open the glove box there are plstic pieces on both sides that keep the glovebox from swinging all the way down, if you push these in the glove box will swing down and you will see a vacuum plug with different colored hoses. If you look back towards the firewall you will see the actuator for the blend door. Its either electric or vacuum depending on the year of your truck. BTW if your truck is a 4wd the vacuum is shared with the 4wd system and could be a leak anywhere from the manifold to the heater control or the hubs on the front wheels, you will have to trace the lines.
John

 

I'll check it again, but is this fixable from the inside glove box or is this something that I have to do outside the truck? Like I said, I checked the back of the glove box and just can't seem to find any cracked wires, everything looks legit but I have no idea where the wires lead to to check them. There's very little space to move around and check things.

 

The vaccum hose you need to check goes TO the black sphere, under the hood.

They have a bad habit of getting broken, burnt, etc.

If that one is good (inspect its entire length) THEN you need to look at the one from the sphere to the glove compartment area.

The sphere itself could be cracked too.

 

since your truck is a 2002 I believe the blend door is actuated by a electric control not vacuum. I am not sure how to trouble shoot it other than going thru a wiring diagram and testing. Maybe someone else will chime in.
John

 

your a/c is run by vac pressure. and the default is defrost. so no vac means no a/c through the vents.



what they said

 

I think I found the issue, but not sure how to fix it.
I'll post pics of my findings shortly...

 

My 98 uses the electric blend door which is located right behind the glove box. on the top of the duct is where the actuator(black or white) is but some other year rangers use a cable connected blind door.

The link between the actuator and blend valve busted in my truck. There is a free fix but I am not certain that this is your problem. When mine was busted I had no temp control and my AC blew only hot air but Max AC worked fine as well as all my other vent controls. https://www.ranger-forums.com/forum2...blend+door+fix

However air seems to come out the defrost vents when the control is set to foot vents. Its not slowly seeking out but its not fully open. It is slightly less air than on the defrost/foot position.

Sorry if it was already stated but where is the valve/valves located that direct air through the vents? I only know where the Max AC valve is.

 

Well I just went outside and took some pics of my findings...

Not exactly sure what's going on but it looks like something got melted... The red wire seems okay:





Please advise on how to fix this issue... I believe this might be why my A/C won't blow out of the vents besides the defrost...

 

Yea my vac. ball thing got a hole in the side of it and it only blew out on defrost. I replaced the ball and it worked fine afterwards

 

Yeah I had to replace one of the lines on my 2000 because I drove around without the fender well, and yeah got a bit mascerated by the tire, oops!

 

So should I replace the line that is melted or the whole ball?

How hard is it?

 

Unless the vacuum reservoir is cracked or otherwise leaking just trim the burnt ends off the plastic lines. Splice in some rubber vacuum line between the two ends and you should be good to go.

 

Where is that burnt end supposed to plug into? The red wire looks secure and good still but that other rubber peace connected to the ball is burnt off and not sure where its supposed to go.

 

thanks for the responses everyone! i wonder if this vacuum leak might be whats causing the cel to be on...

 

Not to thread jack but..... My vents, ac and such work just fine at idle, but randomly when i accelerate it stops blowing from the vents and sends 100% of the airflow to the defroster vents. It will keep it blowing in defrost until im leveled out for a good few seconds. What the heck could be causing this?

Oh and it isnt just if i am at WOT or anyhting, it is at random rpm acceleration. Sometimes when i dont even hit 3k it will stop until im back to crusing speed/rpm

 

One line connects to the intake manifold the other goes thru the bottom of the A/C box on the firewall.

Its caused by a vacuum leak in the supply or control for the blend door actuator. At idle your engine pulls higher vacuum (throttle plates closed). Off idle the vacuum drops (throttle plates open)

 

Just to clarify, the blend door and blend door actuator (BDA) are temperature control mechansims and have nothing to do with air flow or direction.

Airflow (venting) is controlled entirely by vacuum on the Ranger. A leak in the vacuum control circuit may occur during acceleration (slow leak), at all times (large leak), or only when specific functions are selected (indicating a leak in that portion of the circuit).

 

I stand corrected by Rockledge...Meant to write panel/defrost door actuator.