Electrical problems

[Mickyw]

SAAB 93 2005 1.9 tdi vector
Boot lock not working, passenger side rear indicator not woking no plate lights not working. Rear seat lock warning not working boot lock switch not working, found 1 broken wire in loom where boot pivots got all parcel shelf and trim removed all wires checked all fuses checked, main engine management relay swapped no change, put in local garage they couldn’t solve it and gave up, spent hours fault finding,pulling hair out now HELP please

[sgould]

Looking at the wiring diagram, the only common item seems to be the microprocessor in the rear electrical centre behind the trim in the boot. Left hand side.

But they use different connectors to the centre.

The workshop manual (Saab WIS) has a list of the connections and the voltage values at each point.  If you haven't got a WIS it's available on DVD on the internet.

[Mickyw]

Thank you sgould for you swift reply have not got wis but will download it tomorrow, not great on electrical systems but could not find power to the relevant connectors as bought a good voltage tester, the boot lock works as I removed it and tested on battery in shed all bulbs work but to befuddled after that brain about to explode 

[sgould]

The difficulty with diagnosing electrics on the 9-3 is that a lot of the switching is done via the computer networks. The P-bus and the I-bus.  For instance, the indicator switch does not connect to the lights, it sends a message on the network which is read by one of the microprocessors elsewhere in the car. That processor then operates the light.

You may need to find a good local Saab specialist with the Saab Tech2 diagnostic computer to get to the bottom of it.

Whereabouts are you? Someone may be able to give you a recommendation.

[Mickyw]

Hi sgould I am in Dover any recommendations, very frustrating thought I had solved it when I found the broken wire but alas that only solved the sidelight and brake light issue, also I have now noticed the air con fan is not working but that probably a separate issue, I have downloaded the WIS but not been able to view yet as not got enough room on my c drive doh !
I understand what you are saying about the wiring system but it all just makes it harder 

[sgould]

The Tech2 diagnostic can pick up error codes that a general code reader won't, and it can also be used to force things to work (or try to), which can help diagnostics.

There's a list of people with a tech2 here, in another forum http://www.uksaabs.co.uk/UKS/viewtopic.php?f=2&t=126762 expertise varies a lot.