A/C only blows thru the defrost vents. 98 F150
#1
A/C only blows thru the defrost vents. 98 F150
Hello. Have a 98 F150 w/4.? Triton V8. Just recently, the air only comes out of the defrost vents. It is still cold, but blowing on a 100 degree windshield here in FL. does nothing for interior comfort. In reading some other posts, It appears I may have a vacuum leak. Where do I start looking ? Any help would be appreciated.
Thanks
Tom
Thanks
Tom
#3
Ok, Thanks. I started taking things apart and noticed that the big 'door' that directs air into the cabin vents is closed. What actuates this door? It is spring loaded and is closed for the dash vents thus sending all air to the defrost vents. Can I just prop it open somehow? Rarely use defrost here in Fla.
Tom
Tom
#6
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Before screwing around under the dash, pop the hood and inspect the small vacuum line that feeds through the firewall.
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
#7
AC vacuum revisited
Originally Posted by projectSHO89
Before screwing around under the dash, pop the hood and inspect the small vacuum line that feeds through the firewall.
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
Many Thanks
Tom
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#8
Now, if someone could please tell me what each of those lines controls? There are 2 small black lines, 1 large black line, 2 white small lines, and 1 really small black line which I'm assuming is for the AC. Most of these exit the engine compartment through the inner fender wall on the passenger side.
Thanks
Tom
Thanks
Tom
#9
Before screwing around under the dash, pop the hood and inspect the small vacuum line that feeds through the firewall.
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
It is located between the battery and the firewall and is notorious for developing leaks.
When vacuum to the HVAC control head is lost, all airflow automatically defaults to the defroster.
Airflow through defroster only is almost always a loss of vacuum. This applies to all Fords (and probably other makes as well).
Steve
I pressure tested that line and it checks out fine. I'll test again to verify.
Where does the line terminate in the truck side of the firewall??
#11