Cruse/ac wont stay steady

[jgriner]

When I climb a hill or step on the gas, my ac vents change direction. They switch from blowing head on, to defrost. Also my cruse wont kick in extra gas to drive up hills.

Im assuming both the cruse and ac vents run off vacuum pressure, so I must have a leak, right? where do I start? how do I find the leak? Also I very dumb when it comes to engines and stuff (so English please lol)

98 dodge ram pickup quad cab 1500 5.2l


Thanks for all the help in advance

[Tony Silva]

A/C is electronically controlled so is the cruise. Sounds like you need to have your pcm checked out for deterioration.

[jpb53]

It has a vacuum operated servo for the cruise which is under the battery. Acid will drip on the vacuum line a eat a hole in it. Follow the cable the goes forward from the throttle body.

[jgriner]

Originally Posted by jpb53

It has a vacuum operated servo for the cruise which is under the battery. Acid will drip on the vacuum line a eat a hole in it. Follow the cable the goes forward from the throttle body.

thanks will check, is that the same line that connects to the ac vents controls?

[Chris Stewart]

Sometimes a vacuum line will develop a crack that allows air into the system.
You might check those lines, fittings and the little plastic check valves.