Electrical
How to check the Coolant (Water) Temperature Gauge
(Clicking on a photo will bring up a larger image on screen)
Normal operation is for the coolant warning indicator light to flash a few times when you turn the ignition key to the ‘ON’ position and then go off. Once the car is started and the engine warms up, the needle should gradually move to the right. How far right, depends upon the condition of the cooling system – thermostat operating correctly, correct concentration and level of coolant, type of driving, etc.
The ‘temperature sender’ (for the fuel injected Mk2) is located on the top of › Continue reading
Checking Oil Pressure Warning Device (Buzzer)
How the device should work
Test Sequence From 8/81 ->
a) Engine not running – switch ignition on
—– LED must flash for about 3 seconds, buzzer should not sound
b) Engine running
Pull wire (0.5 blue/black) off oil pressure switch and increase engine speed to about 2000 rpm
—– LED must flash and buzzer sound
How to access hidden MFA extras
Hold the button in, turn your ignition on, off and on again
position 1:
Default: Engine code
1: Land code
2: Speedometer
3: Upper rev limitter
4: Lower rev limitter
5: Decelaration fuel pressure
6: Display test
MFA switch on position 2:
Default: Test programm of programmed bytes (checksum)
1: Intake Vacuum
2: Digital rev counter
3: Fuel usage (like normal)
4: Signal from speedo sensor
5: Oil temperature (like default)
6: Ambient temperature (like default)
Here is an alternative list I found on another site:
MFA position 1
Default: Engine Code
1. Country Code
2. Road RPM??
3. Upper RPM
4. Lower RPM
5. No Value
6. Display test
MFA position 2
Default: Program checksum
1. Intake vacuum
2. Real time RPM
3. MPG
4. Speed impulse
5. Oil Temp
6. Outside Temp
Changing Instrument Console Warning Lamp
Carefully ease up the lugs on each of the wiring plug holders and slide them back to release them from the console. Leave the Printed Circuit Board (PCB) attached.
Multi Function Indicator
A number of people have had problems with the MFI in that, whilst the digital clock works and it shows the TIME, OIL TEMPERATURE and AMBIENT TEMPERATURE, it does not show the
DISTANCE COVERED
AVERAGE SPEED and
AVERAGE FUEL CONSUMPTION
If this is the case, then the SPEED SENDER is likely to be defective.
If only the AVERAGE FUEL CONSUMPTION cannot be recalled with the Memory Button whilst driving, then the VACUUM SENDER is defective.
It goes without saying that you should check all vacuum hoses and connections are in good order and not leaking before you suspect a sender fault.
How to replace Steering Lock & Housing
Unfortunately, this job had to be done after the car was a victim of an attempted theft, but this applies if you are changing your locks for whatever reason. In true Scirocco Register style, the procedure is documented here..
Suitable for both Mk1 and Mk2 vehicles.
Tools required:
24mm socket & ratchet
deep 22mm socket for hitting things
Medium flat blade screwdriver
Small philips screwdriver
Molegrips
Allen key – 6mm (I think)
hammer/weighty object.
Parts required:
Steering lock housing (VW: 155 905 851)
steering lock barrel (VW: 191 905 855)
Materials required:
LM Grease or similar
100mm cable tie
Fix your MFA
If none of the functions of the MFA work, including the clock:
The first step is to disconnect the earth at the battery and then re-connect it. This serves to clear and reset the computer memories.
Then check the fuse and whether other electrical items on the circuit work. If they are all ok, then there is either an interruption in the power supply or the earth to the MFI unit, or a break in the printed circuit or the unit is faulty.
To check for a power supply connect a voltmeter to the battery live connection to the dash, not forgetting to connect the negative lead of the voltmeter to a good earth.
You can check this without removing the instrument panel cluster.
How to get power from your Fuse Box
Thankfully a lot of the empty relay slots have access to useful circuits.
Permanant live (AKA Circuit 30)
Relay 1 pin 2 (unfused)
Relay 2 Pin 2 (unfused)
Relay 5 pin 4 -via fuse 1 (radiator fan 30A)
Switched Live (AKA Circuit 15)
Relay 2 pin 4 (unfused)
Relay 3 Pin 5 (unfused)
Relay 4 Pin 4 (unfused)
Relay 6 pin 4 – via fuse 18 (various shit 10A or 15A)
Relay 7 pin 2 – this is acutally x-relief so goes off during cranking.
Relay 2 is mostly used by fuel pump relay, or carb manifold heater relay, but if you’ve got a conversion this may be free.
Relay 6 is for the dual horns, so poverty spec cars will just have a jumper.
Relay 7 is for front fogs, so if you’ve binned the lights, you can use the relay slot for something else.
The rest are mostly used, unless you don’t have wipers 
Other useful stuff that appears on the empty relay slots are listed below:
Relay 2 pin 7 goes live when the starter is engaged.
Relay 2 pin 5 and Relay 4 pin 1 both have a strobed feed from the coil, good for aftermarket tachos or shift lights.
You can use the multiple earth points to the right of the fusebox for grounding all your electrical toys, but if you want more, here’s the earth connections for all the relays:
Relay 1 Pin 1
Relay 2 Pin 1
Relay 3 Pin 6
Relay 4 Pin 6
Relay 5 Pin 1
Relay 6 Pin 2 (not always connected)
Relay 7 Pin 1
Relay 8 Pin 1
Relay 10 pin 4
Relay 11 Pin 4
Relay 12 Pin 4
Obviously the last 4 or 5 won’t be available to you, unless you’re getting creative with the wiring.
Contributor: Forum user SkyRocketeer