the job itself is not difficult although modifying the dash surround can
be(i've got the exact conversion into my cavvy 16v although as per yours
the wirins should pretty much be colour for colour. the only thing you
will need is the gearbox sender plug for the speedo i hope you got this
with the dash as they are extortionate to buy from Vauxhall,
the following is from Cavweb
Cavalier MK3 - Astra GTE digital dash wiring guide
First of all remember an astra digital dash does not have :-
1) 4x4 light
2) check control lights
A cavalier dash has 3 connectors:-
1. large connector, fully populated behind rev counter - does most things
2. large connector, few wires behind petrol gauges - does ABS & 4x4
3. small square one for check control only
An astra Digital dash has 2 connectors:-
large connector like cavalier one which does all lights at the bottom of
the dash small pins with lots of pins which does everything else
Cavalier Connector 1 Astra
Pin Functions Colour Pin
1
2 Alternator Light Blue/White 1 small pin
3 Speedo Blue/Red 21 small pin (and gear box sender)
4 Earth Brown 9 small, 10 small, 11 small, 15 large
5 Illumination Grey/Black 3 small
6 Engine Temp Blue 17 small
7 Fuel Gauge Blue/Black 4 small
8 Revcounter Green 7 small
9 Ignition Black 15 small, 9 large, 5 small
10 Brake Fluid Brown/Red 4 large
11 Handbrake Brown/White 3 large
12 Engine Man Brown/Blue 11 large
13 Indicator Black/White/Green not connected
14 IGN (Ind Fuse) Black not connected
15 Oil Light Blue/Green 22 small
16 Main Beam White 14 large
Indicator Right Black/Green 1 large
Indicator Left Black/White 16 large
Oil Pressure Blue/Yellow 12 small
Illumination Grey/Green 13 large, 16 small
Cavalier Connector 2 - Astra
Pin Functions Colour Pin
1 Seat Belts
2 Airbag (Brown/Yellow too !)
5 TC
6 Trailer Ind White/Green 12 large
7 4x4 Brown/Black To a spare light large
8 ABS Brown/Yellow 6 large
10 Auto Gear box Brown/Violet
11 Glow plugs
12 CAT
You will need to run 2 wires from the indicator switch to the dash:-
Indicator Right Black/Green 1 large
Indicator Left Black/White 16 large
For the illumination and dimmer to work correctly you will have to connect
the
White/Yellow wire (lights on green light) & Grey/Green from pin 16 (relay)
together and run to the fusebox grey/green wire fuse 9 bottom pin.
You will need to add the speedo sender to the gear box and connect:-
black to ignition
brown to ground
blue/red to 21 small pin and Blue/Red wire of the cavalier loom to drive
the 4x4 and fuel computer
Speedo calibration
There is a switch on the LCD dash which changes the speedo calibration
depending
on what tyres you have and gearbox etc.
There are 2 options on the dash (for astra)
175/70*13 (185/65*14 Astra GTE 16v models)
185/60*14 Astra GTE 8v models
You will have to set this the best you can by trying position 1 and 2 and
comparing
the speed reading you get with the fuel computers instant speed reading
found
by putting the fuel computer into average speed mode and then resetting
it.
Even if you get the fuel computer and speedo matching it may still not be
right,
to check follow a car at a constant speed.
To get the oil pressure gauge working you will need to replace your oil
pressure switch
with an oil pressure gauge sender and combined pressure switch.
from a cavalier 1984 GL,CD, Astra Mk1 SR/GTE (about o44 new)
or Astra Mk2 GTE, Calibra 1995 (about o66 new)
The expensive ones have a water proof connector like the cavalier one.
However the o44 is just as good !
If you have an expensive one simply plug in the water proof connector to
the cavalier loom blue/green
And run a new wire from the other terminal (push on) (blue/yellow) to 12
small.
If you have a cheep sender cut off the water proof plug on the cavalier
loom and add a spade. then connect to sender.
And run a new wire from the other terminal (push on) (blue/yellow) to 12
small.
