bergs
New member
The previous owner said something about a vacume line being off. anyway how do i make it blow out of the vents?
my AC/Heat works but only blows out of defroster vents?
- Thread starter bergs
- Start date
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BroncoJoe19
Active member
Simply reconnect that vacuum line 
/emoticons/[email protected] 2x" width="20" height="20" />
The plenum doors are moved by vacuum activated actuators.
Here's a thread with some diagrams for you.
http://broncozone.com/forums/index.php?s=&...ost&p=73129
/emoticons/[email protected] 2x" width="20" height="20" />The plenum doors are moved by vacuum activated actuators.
Here's a thread with some diagrams for you.
http://broncozone.com/forums/index.php?s=&...ost&p=73129
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hmmm... mine has been having the same problem, except it will randomly switch itself from vents to the floor then after a while it will switch back to vents again. I had a jeep cherokee that would never blow air through the vents and it ended up being a vaccum line (freakin' rats chewed it up!). On my bronco however, I cant seem to find any disconnected or chewed up vaccum lines.
BroncoJoe19
Active member
You could try spraying your lines with bubble soap, and when the inside of your truck looks like Lawrence Welk's band just went through it (they blew a lot of bubbles in that show) then you'll know.
Nah... that wouldn't work on vacuum lines. only on pressurized lines.
You could try isolating some lines, pulling a vacuum and seeing if the vacuum holds.
Is it possible that one or more actuators is leaking internally (bad diaphragm?)
Nah... that wouldn't work on vacuum lines. only on pressurized lines.
You could try isolating some lines, pulling a vacuum and seeing if the vacuum holds.
Is it possible that one or more actuators is leaking internally (bad diaphragm?)
BroncoJoe19
Active member
Something from my pull codes thread...
Checking for vacuum leaks.
Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.
Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.
You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.
Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.
Another reader suggested spraying water... it is not flammable.
Checking for vacuum leaks.
Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.
Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.
You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.
Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.
Another reader suggested spraying water... it is not flammable.
