Electrical Problems (SAAB 9-3 Aero 2.0T 2004)

[warptechno]

Hi All

Hoping some kind soul can point me in the right direction. Went to park the car in the in the drive last night and when starting her up i noticed the brake lights were on constantly (even with the fob out of the ignition switch) also when trying the hazards - the rear ones weren't working. So I tried to open the boot with the button to investigate and wasn't working. Tried with the fob, not working. Tried several times and eventually opened the boot. When I tried to close it again it seemed that it wasn't shutting properly.

I took her for a short drive with lights switched on - lights on the dash were cutting in and out and flickering on and off intermittently. Apart from the that the dials on the dash all working fine and no fault displaying on the CEL. Front lights are working fine, switching on and off okay and rears too.

I parked the car up overnight and checked all the lights were off. Went out this morning and disconnected the battery for half an hour started the car back up but still the same. Have had mention on another forum alternator pulley - surely it wouldn't have any affect with this issue when the car is switched off with the fob out of the ignition?

I am thinking along the lines of a relay or a fuse to do with rear of the car. The trunk release button doesn't work now, nor do the rear signal lights and the high level brake light isn't illuminating (when the two lower brake lights are stuck on). It is definitely intermittent though as the brake lights do eventually go out when the fob taken out the ignition switch (last night they stayed on regardless of the car being switched on or off).

I'm pretty good mechanically but electrics are not my strong point unfortunately. I can stretch to reading the voltage with my multimeter so I'll check the alternator tonight after work to see if I can rule that out. Sorry about the waffle.  Cheers guys. 

(SAAB 9-3 Aero 2.0T 2004)

[sgould]

I'll have a look at the wiring diagram when I get back to the computer and see if I can see a common point.

First thoughts are that it could be related to the Rear Electrical Centre in the boot, behind the trim on the left hand side.

Or a possible broken wire between the boot and the bodywork.

The other thing that causes strange electrical problems is corrosion of the wires and connectors underneath the Undebonnet Electrical Centre.  The big block of fuses and relays on the front left hand wing.  It unbolts and can be lifted off three block connectors.  It gets wet under there and strange things go on!

[Audax]

Hoping some kind soul can point me in the right direction. Went to park the car in the in the drive last night and when starting her up i noticed the brake lights were on constantly (even with the fob out of the ignition switch) also when trying the hazards - the rear ones weren't working.

You mean the rear indicators aren't working or? I would suggest you try to get someone to help and test every function for the rear of the car. All the lights (fog, reverse, lights, indicators) using all combinations of switches that do stuff. So try indicators and hazards separately, also try rear heated screen, boot release from keyfob and in the car if the switch is fitted, petrol filler cap release. Reverse sensors if fitted etc. and make a list of what does and doesn't work.

Having a very quick look at the wiring diagram it's probably a control module which isn't something you're going to realistically be able to work on yourself at home or a fault like a bad earth. One thing to ask is does your car have a tow bar fitted? (or did it have one that was removed unprofessionally?).

[warptechno]

I'll have a look at the wiring diagram when I get back to the computer and see if I can see a common point.

First thoughts are that it could be related to the Rear Electrical Centre in the boot, behind the trim on the left hand side.

Or a possible broken wire between the boot and the bodywork.

The other thing that causes strange electrical problems is corrosion of the wires and connectors underneath the Undebonnet Electrical Centre.  The big block of fuses and relays on the front left hand wing.  It unbolts and can be lifted off three block connectors.  It gets wet under there and strange things go on!

Cheers sgould, that is my thinking as well, just seems a little strange that the faults are all pointing to the rear of the car.  Unfortunately, I can't get into the boot to check!  I've been looking into what the boot release button is fused into but no joy so far.  I'll work out how to get into the boot tonight somehow...

You mean the rear indicators aren't working or? I would suggest you try to get someone to help and test every function for the rear of the car. All the lights (fog, reverse, lights, indicators) using all combinations of switches that do stuff. So try indicators and hazards separately, also try rear heated screen, boot release from keyfob and in the car if the switch is fitted, petrol filler cap release. Reverse sensors if fitted etc. and make a list of what does and doesn't work.

Having a very quick look at the wiring diagram it's probably a control module which isn't something you're going to realistically be able to work on yourself at home or a fault like a bad earth. One thing to ask is does your car have a tow bar fitted? (or did it have one that was removed unprofessionally?).

Thanks for the reply Audax, I'll get the Mrs to switch on all the lights etc tonight and I'll check which are working etc.  I know the rear signal lights aren't working from the stalk as well as the hazards button.  Car doesn't have rear parking sensors or an in-car button to release the boot.  The button on the key fob isn't releasing it though.  I also can confirm that a towbar has never been on the car.  Up until now (apart from changing the battery in December), the car hasn't put a foot wrong in 2 1/2 years of ownership - gutted. 

[sgould]

You can get into the boot by tipping the rear seat.  You may need to lift out the rear seat base first (a very hard pull up at the front) so that the backs lie flat.  Not sure if you can open the boot once you are in there though.

The rear seat backrest has an emergency release.  It's the small plastic disc on top of the right hand seat.  Lever it out and you will see a yellow release beneath.

[warptechno]

Thanks for that sgould, much appreciated.  I'll have a look later this evening.

[Audax]

A bit of poking around with the wiring diagrams suggests that this is a fault in the rear electrical centre itself or the wiring. It doesn't appear at first glance that there is any common areas for the hazard lights or the boot release.

The front and side indicators are working right?

[warptechno]

Thanks for having a look Audax.  I got home from work last night and went out to have a look around - used the fob to open the car  and low and behold can open the trunk with the button on the car as well as the fob - all lights working at the rear also  .  The only thing I did notice was a very faint electrical clicking sound every few seconds coming from around the fuse area in the boot (like a relay click but not as loud). This seemed to stop when the fob was in the crank position.  It might be that this sound has always been there but the fact I have my ear down at the fuse box has picked it up - who knows?

Obviously I'll have to keep my eye on things, has the potential to leave the car undrivable but was fine on the way into work this morning. 

Thanks for the input as always - a strange incident indeed and not a lot of info out there - here's hoping it's just a little niggle.. 

[Audax]

Thanks for the input as always - a strange incident indeed and not a lot of info out there - here's hoping it's just a little niggle.. 

There is one other possibility, that rear electrical centre (REC in Saab terminology) does run software as it's a control module and there are updates for that software. The very early cars (2003/2004) had a number of electrical gremlins that after reprogramming and updating the software in the control modules could resolve. If it acts weirdly again it might be worth getting someone to check this all out for you.

[aerojon]

No need to remove the base of the rear seat on the SS,just push the lever on the shelf and drop the seat back down..

[sgould]

I know that the backs drop without removing the seat base, but they won't go flat enough if you need to crawl into the boot as well.

[warptechno]

Sorry to bring this thread back up - I am still having the same problem and will have to bite the bullet and call in an expert to diagnose what's up.  Just wondering if you guys would reckon if this fault would throw up any codes?   Any ideas/similar experience as what to expect cost-wise for an auto electrician to diagnose this fault?  Obviously lots of factors are variable in this case but I'd like to establish a ball park figure to start off with.  I am going to buy a basic obd2 reader and use with torque app anyway- would this give the same/similar info as full tech-2 which I expect the guy who comes out to me will have.

Cheers

[Audax]

I am going to buy a basic obd2 reader and use with torque app anyway- would this give the same/similar info as full tech-2 which I expect the guy who comes out to me will have.

No, it won't have any of the detailed diagnostics that you would get from Tech-2, there is a chance that codes will be logged for this fault. I'd be looking at finding a Saab specialist to investigate rather than an auto electrician.

[aerojon]

I know that the backs drop without removing the seat base, but they won't go flat enough if you need to crawl into the boot as well.

the hinges for the backs are above where the base slots in..