Hi Elk
I think you have the wrong plug. The photos online are the US version.
The plug sits on the left hand side of the glove box (if stting in the passenger seat facing it) Australian models.
4 wires Black red,green yellow, yellow violet. on a green plug.
the receiver unit then sends pulses to the relays. for lock unlock see below.
volvoclub.org.uk/tech/service/850/AntiTheftSystem.pdf check page 16.
You need to confirm what alarm relay is in your car. If you have no working led on the top of the dash you may have a bypass relay in the alarm circuit or it's dead.
or
this explains how the base model one works.
Hi Franz,
I had a 1996 Volvo 850 some years ago to which I fitted an "after market"
remote receiver which interfaced to the Volvo central locking system. To do
this I needed to find out some things about how the Volvo receiver worked,
which I did by trial and error measurements.
The connector for the receiver, behind the glove box is designated 4/19 and
has 5 pins:
pin 1 - wire black (ground)
pin 2 - not used
pin 3 - wire yellow/green (receiver output)
pin 4 - wire yellow/violet (+12V accessory)
pin 5 - wire red (permanent +12V)
The receiver puts out a 100ms (milli-second) positive going pulse on pin 3
to lock the doors and a 200ms pulse to unlock. There was a tolerance of
something like +/- 50ms - I forget the exact figure and it is probably
different for lock and unlock.
You stated that when the failure began the doors would lock (short pulse)
but not unlock (long pulse) - you seem to have made a mistake in your typing
and that's how I interpreted what you wrote. But it doesn't matter anyway.
It looks like either 1) the pulse former in your receiver is "out of spec"
and no longer sending the correct length pulse to the car's central locking
system or 2) the car's central locking system is no longer accepting the
"standard" pulse lengths for lock/unlock.
Unless you have a friend who can trouble shoot the electronics for you, I'd
suggest you get hold of another receiver, buy or borrow one and substitute
if for yours. If it doesn't fix the problem, the trouble is most likely the
central locking module.
Regards
Barry