Saab Tech Tips
Erratic Central Lock Operation on Saab Classic 900
By Don Andrews, Andrews Inc. of Princeton
Problem: Erratic Central Lock Operation on Classic 900
Symptom: Mysterious Central Lock Behavior
This repair is approved by Andrews Inc. of Princeton.
The Repair
We have recently experienced several bizarre cases of mysterious behavior in the central lock system in Classic 900's. Things like locks going up and down on their own while driving down the road, only working when it is raining, only working when it is not raining, and just plain not working!
In each of the above cases the fault was traced to the wiring harness that goes from the main fuse-relay box into the door on the driver's side of the car. It seems that this harness was inserted into a plastic loom for protection at the factory. This is okay except that this loom has also turned into a water trap which has caused the insulation on the wires to disintegrate. Also in this harness are wires for the power window on the driver's side and the driver's power mirror. If you find these wires to be without insulation, they need to be replaced by soldering or butt connecting new wires where needed, then putting heat shrink around your connections. Split open the rest of the loom and remove it so that the water cannot stand around the wires.
This could well solve your mystery lock function and maybe even some other bizarre happenings!
Saab 900 Main Fuse/Relay Box
Fall 1998 Service Bulletin