So I just installed my new 70 dollar Pioneer radio in my truck with the help of my friend Eric. It was a very easy and successful install. Now I have no clue what is wrong with my truck. After we hooked everything back up and started my truck up and turned the a/c on we noticed that this new problem on our hands. The a/c is now only blowing from the top vents that goes to the windshield. we looked at fuses, wires, anything we could think of causing this problem, but we still couldn't figure out why its doing this.

I was wondering if anyone else had this or a similar problem and knows how to fix this without having to take it into a shop

 

if you ARE SURE it was working properly before the install. you may have knocked something loose at the HVAC control under the radio. A/c should not vent to the defroster area.... check the connections on the back of the HVAC control .... just a quick thought. Did you go as far as using a aftermarket wiring harness to make it plug n play? (such as this one http://www.crutchfield.com/p_1207017...e-Harness.html )

 

Its all plugged in, checked it the day we installed the radio and I checked it again yesterday. we used something similar that we got from wal-mart. There was two plugs for the back of the radio but we ended up only using one of them

 

yeah... just offering the possibility

 

You likely damaged (or knocked loose) the vacuum line that runs to the climate control. Loss of vacuum forces all airflow to defroster.

 

how do I check the vacuum line? like its location and such

 

Behind the control unit that is mounted beneath the radio. Here is some quick info I found from another site:


There are two vacuum motors used to control outlet airflow direction.
Item # 1 in the diagram is the PANEL-DEFROST motor, item # 20 is the PANEL/FLOOR door.
If #1 is stuck in the defrost position, you will get airflow from the defrost, but only when the second door is not in the full floor position. If you switch the selector to FLOOR, the defrost airflow should cease.
Need to know whether this is the case or not before giving the next step.
The vacuum motors are controlled by the head unit, whether manual or electronic. (Paragraph was posted along with upper photo referring to an '03)

And a general idea of the setup (this pic was referring to a 95 F150):