Date: Sat, 7 Sep 2002 12:38:34 +0100 From: "Lineone" <lineonenopsamone.org> Subject: Re: 86 900 Central Locking Broken
Maybe I can shed a little light here. I looked into fitting Central-locking to a non-Saab recently, and discovered, at least in principle, how they work. 1. There are two types of solenoids, Masters and Slaves. 2. Typically, the front doors have Masters, rear doors have Slaves. 3. Masters (5 wires) make demands for central locking/unlocking. Slaves (3 wires) simply respond. 4. The system needs a control unit, which: a) accepts demands from the Master solenoids b) meters out control pulses to all solenoids c) accepts demands from the remote control (very often via it's own control unit) d) interfaces with the Alarm system. 5. The metered pulse is of finite duration to prevent the solenoids from permanently drawing current. Whereas I completely failed to find any documentation on the Saab system, I have no reason to believe that it is not typical, though there is one unusual feature, at least in my '92 9000 CS (UK-spec) ...... The Saab system has an untypical element - an Alarm-disable switch (back of glove box), which (I believe) kills both the Alarm and the Central-locking. This switch failed on me about a year ago and the whole car died. Whereas the key would get me into the car, ignition/cranking was disabled. Some £200 later it all worked again. So, the upshot of all this is that when Central-locking fails, you have to consider the following elements: - Solenoids - Control unit - Alarm-disable switch (if present) - Wiring & fusing HTH. > >> I *think* you'll find that the "control unit" is a switch physically > > linked to the drivers' door lock - the turning of the key actuates the > > switch, which then sends the signal to the other solenoids in the car. > > > The manual says it is. Manual says it turns on for about a second every time > > the driver's door switch changes. > > OK, that's very surprising, but of course I'll defer to the manual you have.