A/C & heat ONLY comes out of defroster...not vents!

[CMLJESSE]

Ok, this is weird!'

2000 Ford Ranger, 2.5L 4-cyl.

Regardless of whether I have the air or the heat on, it will only come out of the defroster! Even if I have it on heater, or vent, or anything, I only get blowing out of the defroster!

Any ideas??

 

[TireIron]

you most likely have a vacuum leak somewhere because those are controlled with vacuum. Do some looking around in your engine bay for vacuum leaks and check the lines going in through the firewall on the passengerside. A vacuum leak anywhere in the system can cause the vacuum to be low enough for the heater control doors to close to the default position which is defrost.

 

[CMLJESSE]

Thanks!!!

 

[ZackB]

Please let us know if you find anything, I'm having the same problem and have checked quickly and haven't been able to find anything. Once it warms up I'll have to dig deeper.

 

[fordwheelinman]

It could also be a broken mode door. I have seen it happen more than a few times.

If you can take your glove box out of the dash remove it, then see if you can feel up on top of the heater box for the actuators for the mode and blend doors. If you can, let the truck run for a few moments to build some vacuum, or leave it running, then turn your selector knob on the controls and see if you can feel the actuator moving. If you CAN, the problem is most likely a broken door, if you CAN NOT, then you most likely have a vacuum leak or a bad actuator. I seriously hope for your sake it is not a broken mode door. Best of luck to you friend, FWM.

 

[CMLJESSE]

I won't be able to get under the hood until next week (taking a week off from work!), then I'll be able to check it out. I'll let you know if I find anything.

 

[ZackB]

Update. I was poking around under the hood, I figured since none of the actuators worked the problem must be in the main vacuum feed line, and was getting vacuum at the input to the round vacuum storage black thing under the coolant reservoir and I noticed there was no vacuum on the output to the dash. Well there must be some sort of check valve in there because I swapped the in and the out and wala the actuators now work, woohoo. Now back to reality and in my poking around I must have loosened something because now there is a battery light on the dash, oh well.........