Starting!

[steves1275]

Hi
I'm hoping to find some help!
We have a Saab 93 which has an unusual problem
Intermittantly the starter motor will try to engage whilst the engine is running!
It makes an horrific noise!
Turning off the ignition will stop the problem, however, just turning the ign 'on' will start the car. It starts before the start position is reached!
I have tried an ignition switch to no avail.
Has anybody any thoughts or has anybody exoperienced this before?
Can anyone supply me a copy of the starter circuit wiring diagram.
Its a 2007 93 convertible automatic.

Thanks
Steve

[Audax]

Sounds like the wiring from the ignition switch to the CIM is shorting out somewhere, the cabling can rub through on one of the metal stays in the footwells from the ignition switch forward where it's cable tied on from memory. If you remove the passenger side covers front and back you should be able to trace the wiring and find where it runs, remove the fabric coating and check very carefully for any shorts/rubbing.

[sgould]

Welcome!

What Audax says makes sense for an erratic fault.  The CIM is the Column Integration Module on the steering column with the wiper/indicator stalks coming from it. If you find the wires are OK, it gets more difficult.  The CIM links to the Power bus (P-bus) which controls the relay.

I'm assuming that this is a petrol engine?

The only source of power to the starter motor is from the starter relay in the fuse box on the front left wing under the bonnet (see attachment).

Either the relay is faulty or the control circuit to it is faulty and switching the relay on at the wrong time.  There are only two items controlling the relay switching.  The computer (P-bus) and the automatic transmission range switch.  The range switch is the bit that sits on top of the gearbox and swivels when you move the selector.  It has internal wiring and switches and controls the starting inhibitor, so you can only start in P or N.  It also controls the reversing lights.  I've not heard of a range switch failing in a 9-3, but it has been a common fault on the earlier 9-5's.

If it's a P-bus fault, you will only find it by getting the fault codes read by a code reader, to be absolutely sure, you need a proper Saab diagnostic computer at a Saab authorised repairer.

Fuse 6 under the bonnet controls the range switch.  Maxi fuse 31 provides the power to the starter via the relay.

Possibly the only thing that's DIY is to swap the relay.

[Petemate]

Modern cars are so complex.....fully endorse all that, seems like an inhibitor fault but of course as per sgould, many places to check. On something nice and simple as the old cars, had quite a few Austin 3-litres out of the mere 10,000 they made at Cowley with faulty inhibitor switches, but faults like that are a s0d to find on a car which has never been on the road. At least with yours, you have eliminated the switch so as said probably/possibly the relay. Good luck and let us all know!!

[Audax]

Just to be absolutely clear on this, the reason I'd check the wiring from the ignition switch first towards under the dash, I've seen it chafe through on more than a few cars causing very similar problems with the ignition switch.

If it isn't that then I'd be heading for the CIM or the front fuse board, although at this point you'd be better off with a specialist/dealer who has a Tech-2 to get codes pulled. At very least you'll need to know how to use a multimeter and have a copy of the wiring diagram.

[sgould]

Here's the wiring diagrams that I can find.

First one is the starter motor(4), relay(517), range switch(245)

Second is the ignition switch(20), CIM(703), steering lock(708)

[Saabman]

I'd also suspect a wiring fault, but also check that the front fuse box behind the n/s headlamp is water tight as if water gets into the fuse box it shorts the terminals and switches various/random things on  Check the lid is on properly 

[aerojon]

i'd start by replacing the relay,most 12v relays have a hair spring inside which pulls the contact plate back once the power to the coil have been cut..