I have a heater core leak, as well as inoperative air conditioning on my 2001 S80 2.9. I'm guessing the issues aren't related, but is it possible to inspect the a/c evaporator with the heater core removed? Perhaps with a borescope? I do plan to inspect the evaporator drain per this guide.
Also, here is what diagnostics I have done on my a/c, in case anyone has advice.
- The compressor clutch will activate when jumping relay in fuse panel
- I used one of the low-side fill kits (I know this isn't ideal) to inject R134a with UV dye. Compressor engaged, and I let it run.
- A consistent hissing sound comes from within the dash with a/c running; this makes me think evaporator or expansion valve leak. Maybe it's just a result of low refrigerant?
- Compressor eventually wouldn't engage; presumably enough coolant leaked out. When I re-attached the low-side A/C coolant again, the gauge still shows pressure when the a/c switch is off.
- This part leaves me confused. Now when I turn on the a/c switch, the low-side pressure drops to zero, even though the compressor is not spinning. It's also not taking any refrigerant, judged by weighing the can.
- I haven't found any leaks under the hood, but I haven't removed the bumper cover to inspect the dryer & condenser.
- I do plan on getting a real manifold gauge set and vacuum pump.