Date: Fri, 14 Nov 1997 06:48:34 GMT From: Ywan Mason <ymasonnopsamsouth.net> Subject: Re: 93' 9000CSE Heater Question &Various other questions
The 93 9000 uses a somewhat more complicated fan temp sensor along with its two speed fan. Check that the fuse for the fan is not blown, Saab changed the rating on it to one step higher than what came in the car (from a 25 to a 30 amp fuse) there will be two fuses for it in the engine compartment fuse box, one for low speed and one for high speed. Change them both. The sensor is prone to having wire damage, so make sure the wiring at the sensor is good. It mounts in the lower right of the radiator on a 9000. Make sure the car has a factory 82 degree thermostat in it. After market thermostats do not incorporate some of Saabs engineering and cause a loss of coolant flow or overheating. Our shop changes the thermostat as part of every major service to prevent overheating from thermostat failure. $30 tops is cheap insurance. We also flush the cooling system at the same time and use Mercedes Benz coolant which is silicate/phosphate free and specially buffered against pH changes. With its use, our shop has seen a tremendous decline in cooling system failures of all kinds. At $10 a gal, its cheap insurance as well. Running the car hot will lead to head gasket failure eventually. It does nothing for your gas mileage and engine seals either. Hotter engines are also more prone to spark knocking and this limits performance. On the heating system, make sure both hoses going into the passenger compartment on the left side of the engine compartment get hot when the engine is at operating temperature. Someone could have tried stop leak to "fix" the heater core leak and this could be stopping up the core and the radiator, causing both your no heat and over heat conditions. A 9000 flows coolant through the heater core all the time, whether you have the heat on or not. It directs the cabin air through the heater core or not depending on what you request for a temperature in the cabin. If you remove the plastic cover on the right side of the engine compartment near the windshield and look in just right of center, you will see a cable like a bicycle brake cable coming from the interior to a white plastic arm controlling the heat flap. This flap controls the flow of air over the hot heater core. On ACC systems, the motor driving this cable can overextend and break the arm off. The ACC doesn't record a code for this problem. Saab has a $7 kit that will both repair the broken arm and prevent the motor from overextending again. It is easily installed in less than an hour by even a first timer. Ask a dealer for part number 7496433. The ACC system has self diagnostics and will show you the number of codes it has stored from its self test when you start the car up. If no codes are stored, it will display your selected temperature in its display. If you see a 1 or 2 or such when you start the car up in the ACC display for a while, the system has faults. The broken arm will not set a fault as the computer monitors the position of the motor which is usually where it should be, not the position of the actual flap that controls the heat. I recommend you get the heater core attended to as soon as possible. The coolant is dripping into the interior of the car and will eventually rot the carpets and floor panels. Not to mention the smell and the inconvenience of topping off the reservoir constantly.