Ford F150 - A/C pump problem

When my AC or defrost is on the pump kicks on and off with a audible tick. In turn the AC is cold for about a minute or two than it doesn't stay cold. This also effects the defrost too. I checked my r134a pressure and its on the high side of where it i supposed to be. I can see the AC pump turning on and off and the tick comes from when the pump stops turning. I am thinking that it may be the AC clutch. But i don't know for sure. Any one have any ideas. This is on a 97 f-150 with a 4.6. Thanks

make sure that the refrigerant is full. you may have a leak in the system. there is a clearance for the a/c clutch but i am not sure what it is. steve83 would probably be able to answer you on the clearance.

It has to be a low charge making it cycle excessively. Get a pro to find & fix the leak. A/C work requires special equipment that's not cost-effective for the home mechanic to buy & learn.