Whenever I select heat my a/c clutch kicks on. I pulled the fuse on the clutch and I still don't have adequate heat. Changed thermostat for good measure, flushed system, checked valve on input line to heater core, swapped temp selector switch and heat/air switch, checked door beside the heater core, swapped a/c relay. A/C clutch still engages whenever I select heat. Any ideas boys. Getting a little frustrated. Thanks.