a/c shuts off at high rpm's in bronco

The a/c in my 92 Bronco shuts off when I go over 1800 rpm's. Air still blows out the top vents instead. When I slow down the a/c kicks back on in the vents. What could this be?

Your post may have been better titled as

"my air flow diverts from vents to defrost when engine accelerates or runs at higher rpm"

This is a typical vacuum leak in mode door vacuum line under hood scenario. Trace the black plastic vacuum line from firewall to vacuum reservoir to intake manifold - see if it is broken or cracked or deteriated- the cut out bad portion or add new.

The mode doors are spring loaded such that if there is a loss of vacuum (your case) that the air flow goes to defrost for safety - so as to not allow foggy windshields and inability to see where you are going.

thanks for the help. your right i did not phrase that correctly. I had to redo most of the vacuum lines. they were all melted closed or broke. Thanks again for the help.

Hey I drove over a pot hole and my check engine light came back on. I had got it to turn off by replacing the vacuum hose on the egr valve. I checked all the lines and they are secure so I can't figure out why the light came back on. Any ideas?

In my opinion, the air condition shutting off at high speeds, can be because of a blown fuse in your automobile.

The IDL which maintains the cars Revolution Per Minute (RPM), could have got either dirt, dust or oil in the actuator, which could explain why the air condition shuts off at high rpm's.

Since the IAC is directly tied to the engines electrical units, like the air conditioner, it is suggested that the engine caused a plug t
o misfire, causing a break in the current.