Hello I have a 1996 Dodge Ram 1500 with the 5.9l engine. I noticed today that there was something clicking on/off several times while the engine was running. I popped the hood and found it was the A/C compressor cycling on/off for some unknown reason. I had the defrost on and the temp. control on slightly warm. Any ideas as to why this is happening ? I don't believe this would be a normal operating condition.:confused:

It's Normal.

If the outside air temperature is cold, say 50 degrees, it has to do that to keep from freezing up. Normally a very good AC can drop the temp 15-20 deg which means the evaporator can freeze. Recirculate mode may even make it worse.

Very helpful

For many years now, engineers and programmers have known that with most vehicle cabins built with better seals, short cycling the A/C compressor during Defrost mode can greatly reduce the amount of moisture inside the vehicle's cabin, thus clearing the windows more effectively.
With most vehicles built in temp sensing measures, freeze-up has pretty much been eliminated during cold weather.