2006 93 Aero: replaced alternator, and battery, still won't start

[Nick an]

I will try to be brief and to the point: my otherwise perfectly kept 2006 93 Aero has stopped running. Wouldn't start at all, no sound, nothing. I replaced the battery. Car worked for a couple days then stopped. Dealership "Tested" the car and determined it needed a new alternator. I opted for a used alternator ($1,000). Got the car back and the next day, it wouldn't start. Dealership said I needed a new battery! The battery I had just purchased was dead. They said the alternator issue caused the battery to fry. Fortunately Pep Boys replaced it for free. The car worked for 1 day and is now not starting again. Added information....my windows, moonroof and radio were all acting up prior to all of this starting. Now my radio doesn't work at all. The dealership said the alternator caused my radio amp to fry and would cost me another $1000 to fix. I am at my wit send with this dealership and their repair shop, and am seeking thoughts as to what could be happening with my Saab.

[9-3 Aero]

The culprit could be increased parasitic draw from the battery, which is fairly easy to verify whether or not is the case, and the first action I would take as a troubleshooting measure. Disconnect one of the battery terminals and give the battery a "good" charge (hours). Then connect a multimeter, with a fair amps range (in case high current reading), in series with the terminal and reconnect it. The measurement to be done 25 minutes after the doors were closed (ignition OFF) to let all electronic modules "go to sleep". The parasitic current should not be > 20 - 40 mA. The measurement could be performed with a clamp-on device as well, to provide amps range as needed.

Ignition switch is a known part causing this kind of problems, as it connects - and shall disconnect main power sources. I'm currently dealing with a similar case (9-3 MY2003) on another forum, where loss of power / increased parasitic draw was caused by a short in the audio AMP1.

[Nick an]

Thank you for the quick I reply. I will certainly look into the suggestions you pose. Seeing as the battery is BRAND NEW, as in three days old, do you think I this parasitic issue would drain a new battery so quickly? The ignition switch sounds like a real possibility. I would think a decent dealership who services Saabs would know to do all of this.....

[9-3 Aero]

In theory, and for all practical purposes, could a brand new battery be drained in three days. If, for instance the current draw is 1A, that'll be 24 amps a day, and with a 60 - or 70 Ahrs battery - ! The less power on the battery, the faster will it be discharged.

Now, whether 1A is an expected, abnormal draw or not, can be questioned. An normal parasitic draw before the modules go to their sleep modes will be in the 150 mA range, or so, to give an idea what's going on when the key is pulled.

[Tball]

My 04 Saab battery died so I used a boost start and it cranked but never fired. So I put on trickle charge and waited several hours, it now cranks and everything works but it just will not fire I tried resetting the ecu. I can hear the fuel pump priming, so I don't believe it is that. Any help is appreciated I can't seem to figure out how to post a new thread.

[9-3 Aero]

Welcome to the SaabWorld

Priming fuel pump is a good sign, although "pressure" could be a different animal.

Low battery voltage means increased current in some circuits, and boost starts may impose secondary effects. Not knowing whether you have or not, are fuses #4 in the centre in front of the battery and #2 and #4 in the UEC (between the battery and the sidewall) to be checked.

To post a new thread: Simply select the "Post New Thread" on top (or bottom) of the forum in question. Don't forget the title, with a brief description of the issue.

[Tball]

i replaced fuse 4 in uec on a hunch even though the fuse was not bad and it started but died immediately, tried replacing it again and a to square one cranking but no firing. i have checked the others and they look fine. the car did have motor replaced with used 70,000 mile engine last year could it have lost map settings with a dead battery? it has been really cold here in Ky could that have caused any problem? also could a bad cell in the battery allow it to crank and not fire? on another note i believe there is a parricidic drain as the battery has died multiple times over night. i have noticed that some back lights stay on like the cd changer buttons and the lock/window switch lights with the key off and out of the ignition even with doors closed.

[9-3 Aero]

The Saabs are famous for their odd behaviour when battery is detoriating. How did you "reset" the ECU? It's interesting to note that it now started after fuse #4 was replaced (out for some seconds) as it is a part of the supply for the ECU.

How old is the battery? Given the battery now has limited capacity, what I would do is trickle charge it again for - hours, then remove the charger, wait maybe half an hour and measure the voltage on the terminals of the battery. If lower than 12.3V, the battery is at least questionable. Then, pull the two #4 fuses for half an hour to "reset" the ECU - and try starting.

Cold weather / battery capacity: A 70% charged battery at 68°F will have 35% at ÷0.4°F!

The paracitic drain could be the lights you note, or the battery if not in a good shape.

[Tball]

to reset the ecu i took off negative cable and pulled fuse 2 for 10 minutes.

could a bad battery allow cranking but no starting?

[9-3 Aero]

Generally speaking - no.