This post needs the help of a Peugeot electrical specialist.

Peugeot 205 central locking started playing up when the master switch on the
driver's door started buzzing when the lock was operated and only the boot
locking motor was operating. I bought a new master switch (£58 !!) but the
fault is still the same except the switch does not buzz. Looking at the
circuit diagram and by some electrical diagnosis, the master switch has a
12v input on 2 spades and outputs either +12V or -12V depending on the
switch plunger position on another 2 spades. When the switch plunger is
moved there is what looks like +12V at the output for about 1 second or so
then drops to 0V. Move the plunger the other way and there is -12V for 1
second, then 0V. This seems to be to drive the other 4 lock slave motors in
one direction or the other to lock or unlock each door. That's the theory.
But ... with the master switch output plug disconnected, I get +/- 12V at
the switch output, but with the plug connected I get about +/- 5V, and when
the output voltage rises say to +5V, the input voltage drops to about 5V or
so, then recovers to 12V again. Its hard to say what the actual voltages are
since they are only present for a second or so reading it with an analogue
voltmeter. But how can the input voltage drop so much, even with say only
one slave motor connected, the boot one, the supply is supposed to come
straight from the fuse box. Each of the slave motors is connected in
parallel across the output side of the master switch and I have continuity
checked each plug to each plug and all the wiring between seems intact and
not shorted to earth.
The only slave motor that wants to move is the boot one, but it is smaller
than the other 4 and a different design.
Another odd thing is that the Haynes wiring diagram does not show a slave
motor on the driver's door, but there is on my car. The electrical
connections are by means of 2 bullet type connectors, whereas the other 3
doors have a square connector with 2 spades.

Please can anyone help here. I have all 4 door's trim off and have to use
the car to work each day.

Thanks

Wolfy

On Thu, 10 Jul 2003 22:26:00 +0100, "Wolfy" <wolfy@q%6Gvv.co.uk>
wrote:

do a con check from the battery +ve to the master switch input. i bet
its a lot more than zero ohms!! if so then all you have to do is
locate it. repeat from fusebox to switch, battery to fusebox etc till
you find the gremlin.