Where do you add oil after replacing AC evaporator for Saab 2001 9.3?

If you are adding coolant/water every week and there are no external leaks, you are probably burning the coolant thru the engine.
You can burn a large amount and not see any smoke from the exhaust pipe. Possible head gasket or cracked head.

IN THE COMPRESSOR USUALLY ADD 2 OUNCES,PUT THE OIL IN THE HOLES WHERE YOUR LINES WILL GO.

NEW AC COMPRESSOR POUR OUT SHIPPING OIL COME WITH IT ADD THEM SAME AMOUNT.IF YOU NOT SURE AND OIL BEEN POURED OUT.ADD 2 OUNCE R 134A REFRIGERANT OIL TO NEW COMPRESSOR. YOUR AC SYSTEM HOLD 1.75 LBS R 134A REFRIGERANT.

when replacing compressor you should drain/measure the amount of oil in old unit
then add equal amount of clean oil.if no oil is in old unit then adding 2 - 4 oz is recemended
compressors are shipped dry & reciever dryer or accumalator should be replaced as well
adding 2 oz of oil.

good luck

You removed the AC compressor? DId you block it in like A-6 compressors or just open the system? If you did not block it in, then you are required to flush the whole system replace the R/D or dessicant and check the OT or EV. Then you add the oil or seal and add oil charge and evac it and then charge it. This is not going to be cheap. You could have just R/R the clutch without taking the compressor off.

OK, most cars have heater cores that get hot but the blender door directs air away from this core in the a/c mode when you want cool air from the evaporator.

I'm not sure if there is a control valve which stops the water from going through the heater valve.

I think the part is called a 'heater blend door actuator' that you are after.
http://www.autoanything.com/air-conditioning-65-861/201A1060.aspx?kc=AFFCJ&mr:referralID=c9ca506d-9f22-11df-bf8d-0026b95a1738

doesnt mean system is empty,because no oil came out off compressor,unless the system was flush and should be flushed with cleaner, then the system would hold 10oz, of oil,also make sure to spin compressor by hand 10 times to get the oil and liqiud out of cylinders,add a couple ozes of oil in dryer then compressor and the evaporator core to equal 10oz of oil,after added oil to compressor stand on pulley to coat seal let sit for 10min, then after all line are connected then you spin 10 turns, hope this help,

where did the oil go that was in there? it doesn't evaporate, u have a leak, check around the hydraulic lift cylinders, that is where the leaks occure.

first off your mechanic sounds like he's taking you for a ride! If the oil lights coming on you need to check your oil pressure. I wouldnt drive this car anymore till I knew for sure I was getting good oil pressure through out the motor. Find a different mechanic! Mechanics are some of the biggest lying thieves! Right up there with lawyers.

highley doubt it because you serpentine belt is on a torque pulley, and you should have added ac refrigerant to a nozzle usually covered by a blue cal about the width of a dime, add the refrigerant to that one