A/C vents not blowing a lot of air

Tiny
MRDIXON
  • MEMBER
  • 2006 FORD RANGER
  • 2.3L
  • 4 CYL
  • 2WD
  • MANUAL
  • 113,500 MILES
When I turn on the a/c or heat there is very little air blowing out of the vents. The fan is working fine on all speeds. After driving for about 15 minutes the air flow increases but it's still about half of what it should be. It's the same for heat and defrost. Low air flow to start but increases as I drive the truck. All vent positions are working. This happens when the a/c is in the max position and the normal a/c position. It heats just fine too.
Friday, October 24th, 2014 AT 7:19 AM

17 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
Have you verified that it isn't coming out a different vent like the defrost?
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Friday, October 24th, 2014 AT 8:05 AM
Tiny
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Yes I have.
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Friday, October 24th, 2014 AT 8:48 AM
Tiny
WRENCHTECH
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Look under the dash on the passenger side and verify that it hasn't sucked a plastic bag or anything like that into the air intake. If you happen to have a dog that rides in the car, it can suck the hair in and plug up the holes in the evaporator not letting any air through it.

This is all assuming you haven't had any recent repairs to the AC system.
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Friday, October 24th, 2014 AT 11:07 AM
Tiny
MRDIXON
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I checked the fan compartment. Nothing in there. I just bought the truck a couple of weeks ago from a guy. He told me that it hasn't had any repair work other than the usual upkeep. The truck has 113600 miles on it. I've checked the vacuum lines that I can get to. Don't see anything loose. Is it possible for the a/c vacuum reservoir to be bad. Maybe not holding enough vacuum to fully open the vents? How would I check it?
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Friday, October 24th, 2014 AT 12:43 PM
Tiny
MRDIXON
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How can I get to the evaporator core to see if it's plugged up?
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Friday, October 24th, 2014 AT 12:45 PM
Tiny
WRENCHTECH
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I already asked you if the air was coming out through different vents and you said no. That's the only thing a vacuum problem would do. If you don't have a mode direction problem, then you have to have an issue with the blower motor or something restricting air flow. You may be able to see the evaporator if you remove the blower motor.

https://www.2carpros.com/images/external/06Rangerblowermotor.jpg
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Friday, October 24th, 2014 AT 3:11 PM
Tiny
MRDIXON
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Ok.I'll remove the motor and fan and look at the evaporator. Probably tomorrow.
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Friday, October 24th, 2014 AT 3:59 PM
Tiny
WRENCHTECH
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Make sure the blower motor cage is clear too. Mice have been known to nest in there.
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Friday, October 24th, 2014 AT 4:06 PM
Tiny
MRDIXON
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Ok. Would it hurt anything if I removed and two main vents and blow air back thru the ductwork with my leaf blower? I'm thinking if the evaporator has blockage that blowing air back in the opposite direction my clear it out a little.
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Friday, October 24th, 2014 AT 4:10 PM
Tiny
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I wouldn't. Not only will it not help but you could damage one of the are doors. If the evap is plugged up, it will be stuck to it like glue. Pet hair is the only thing I have ever seen block one that bad. It will stick to the core and harden.
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Friday, October 24th, 2014 AT 4:14 PM
Tiny
MRDIXON
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Ok. That's out then. I don't know if the other owner had a pet in there or not. No hair in it anywhere when I bought it but he could have cleaned it up before he sold it to me.
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Friday, October 24th, 2014 AT 4:18 PM
Tiny
WRENCHTECH
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You need to be real sure that this isn't just misdirected air.
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Friday, October 24th, 2014 AT 4:21 PM
Tiny
MRDIXON
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Ok
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Friday, October 24th, 2014 AT 4:35 PM
Tiny
MRDIXON
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Hey.I just got around to pulling the fan. After I got it out I looked around at the evaporator core and saw a lot of ground up leaves and dirt. I vacuumed out what I could. Used my compressor to blow air around it to loosen more of it. Vacuumed some more. Repeated this process about 10 times until I couldn't get any more out. I put it all back together and now the fan blows like it should. Plenty of air! Thanks for your help and suggestions!
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Sunday, November 2nd, 2014 AT 2:14 PM
Tiny
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Glad to hear you were able to resolve it.
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Sunday, November 2nd, 2014 AT 2:17 PM
Tiny
MRDIXON
  • MEMBER
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Now I have another problem. When I first cranked up the truck this morning the check engine light came on and stays on. I took it to Advance Auto and they told me theThe OBD code is PO171. What ever that is. I checked everything I could find. Vacuum hoses. PVC. Etc. And couldn't find anything loose. Suggestions? Will it hurt to drive it until I find out what this is?
Thanks again
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Sunday, November 2nd, 2014 AT 2:18 PM
Tiny
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You need to start a new question for the new problem.
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Sunday, November 2nd, 2014 AT 2:21 PM

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