I recently put a newer 302 into my 81 f100 Ranger Lariat. I also installed and serviced a new A/C compressor and condenser. My compressor cycles on and off every few seconds with a vibrating noise coming from the heater core/blower motor area only when the compressor cycles on. it is louder with RPM increase. The fan blows air but not cold air or heat......any ideas?

 

When it cycles on and off there are a few things it could be. Did you have it serviced by a shop? One is that there is not enough coolant on the system. One other is that the condenser is not cooling what you have and finally, the orifice is bad or not correct for your area. If done by a shop, have them check the coolant level for proper poundage first.

 

By coolant he means refrigerant or some people like to call it freon.

 

Or some call it charge
Dave ----

 

Did you check that the vent door that switches from AC/heat is working the hinge on those wear out and break That could be the noise your hearing

 

well I had a friend do the 134a servicing.....guess that's my first mistake. Today I had my hand on the blower motor while the compressor cycled. It feels like the bearings are shot. I'll replace that after Christmas. I'll check the vent door then as well. I will just take the truck to an A/C shop after I get the vibrations out of the blower. Thanks to all who replied for the heads up.