Hey everyone. Just got a free 2000 Saab 9-5 Aero from my brother and it has some quirks. The car has the 2.3T engine with an automatic transmission. The first issue is that it will start 100 times more or less in a row and then it will not start. All of the dash lights come on like normal but the car will not start and will not make any noises at all. No ticking, clicking or any sound at all. Every time it was taken back to the repair shop it would start up after the tow truck ride. The second issue is that the heat / ac system works fine but no heat will come out of the vents. The fan works fine and it will switch from the floor to the dash to the defroster vents just fine. It is like no coolant is getting to the heater core. The third item and last is the driver’s seat electric adjustments will not function unless you pull the fuse put it back in and turn the ignition on and the seat will move. If you want to move it again you need to start over.
Next time it doesn’t start, put a block of wood onto the starter and hit the block of wood with a hammer. If it now wants to start, your starter (and/or starter solenoid, which sits on top of the starter) is likely due for replacement.
If the valve is in one of the heater hoses, then yes, I’d guess that valve should open when you want heat. The valve may be stuck, or the vacuum line may be cracked or leaking. I’d check the line first, see if it changes from no vacuum to vacuum when you go from vent to heat (or vice versa, I don’t know which would be the ‘no heat’ position).
Stone silence with a no-start condition can often be attributed to a faulty neutral safety switch. This switch is what prevents the engine from starting in anything other than PARK or NEUTRAL. Next time it acts up, move the shifter back and forth before another start attemp or try to start it in NEUTRAL and see what happens.
A poor connection at a junction terminal can also cause a problem like this and is usually located near the battery positive terminal on the chassis.
As to no heat, maybe there’s a problem with a blend door.
What did you ever do to your brother that he hates you so much? In addition to the others, I would make sure you have good and clean battery connections and I’d freshen up all of the battery cable and ground cable connections just to take that out of the mix. Also sometimes the battery cables can look fine but be bad inside. Agree to take a look at that water shut off valve if there is one. They were used to shut the hot water off to the heater core when using the air conditioner. May have just stuck or maybe shot. If not, check the flow through the heater core and maybe flush it out. On the fuse, replace the fuse, take some fine wet or dry sandpaper or a file or whatever you can get in there to freshen up the contacts, or even electrical contact cleaner, or try some bulb grease or electrical contact grease on it. There must be deposits causing a poor connection. Good luck.
I think the no-start problem is most likely due to the neutral safety switch as mentioned above. It may just need adjustment. Or may need to be replaced. The 2nd most likely cause is a faulty ignition switch or starter relay. (The starter relay – if your car has one – would be on the passenger compartment relay panel probably. Maybe get a schematic and check if your car has one. I’m not talking about the starter selonoid contacts. If they were bad, you’d still hear a click.) In would be prudent to clean both battery terminals and resecure the connections too, as bad battery connections can cause problems like this sometimes, especially when it gets cold.
One thing you can do to diagnose the indoor heat problem is locate the two coolant hoses going through the firewall to the heater. When the indoor heater is full on and the fan is blowing on “hi”, one of them should feel quite hot, and the other noticeably cooler. If not, then most likely either the heater core is plugged, or the heater control valve is not working. If you car is past its service interval for coolant change, it would be prudent to have the cooling system flushed and new coolant put in.
The no start is probably as ok4450 stated; when the car fails to turn over, check for 12V at the starter solenoid. If none, put a bag of ice or pour cold water on the neutral safety switch (right under the corner of the battery tray). If that makes it work, its definately the switch failing open when it gets hot. Could also have a failing crank angle sensor - also a known fault on these cars;
The HVAC issue is likely a broken stop arm on the blend door shaft. You can calibrate your ACC unit and check for trouble codes by doing the following: a) Start the engine and press the auto and off buttons on the AC control and release simultaneously b) The HVAC and blend door motors will run through a self diagnostic. Do this diagnostic 2X to make sure you are getting all the codes - sometimes it’ll run with no faults and then if you do it again, you’ll get the blend door or other error codes. The number of faults will be displayed on the left, and the fault code(s) on the right. Blend door issues usually present with a code 08 on the left side, or code 11 on the right. The left (drivers side) is the most likely one to break. You can fix this in less than an hour. A new blend door stop arm is about $20 - $30.
Good luck - you got a really nice free car; get those small items fixed and you’ll be in good shape.
BTW - sorry forgot to answer your 3rd question. These seats normally have 2 relays (power, w/o memory) each. Try swapping the under seat relays from the passenger to the drivers seat. If that fixes it, you are all set.
