mfa problem

Struggling with mine all day today as only the clock works! Used to work before it went in the garage for 12 years. Pretty sure though that it doesn't matter how long the vacuum tube is as long as it's connected at each end.
I have a feeling and it's only a feeling but I suspect most of the problems with the MFA is down to the switches on the stick. You used to be able to buy them fairly cheap from German and Swedish back in the day but not sure where to get one now. Second hand is likely to have the same problems.

Do you get the outside temperature?

hello, if the ends are both connected, the external temperature is displayed, they press the mfa button, the cursor moves but only displays the dashes as if it didn't read

Just checking…. you do need to drive/move the car for the MPG, average speed and distance traveled to work..

So I guess you have clock time, time traveled, oil temp and out side temp all working as it should?

  

it does not read the average speed, fuel consumption, while driving time and outside temperature, clock and engine oil temperature work

Does anyone out there know how to test the switch on the stalk?

if you dont get distance/speed/mpg then the speed sensor on the back of the speedometer isn't working.  The sensor itself doesnt usually go bad but you can try another. Usually its the blue pcb foil which has damage, or in my case it was the pickup ring inside the speedometer which was at fault.

for MFA switch testing first follow the wiring form it, one pin is earthed with the dash clock to the side of the head, brown/white wire.  if this has gone bad in the past and the PO just cut and ran the cluster earth to the chassis, then the stalk earth would be missing.

if you jump each pin of the stalk to earth it will trigger the corresponding mfa functions, the first question is what stalk/clock setup do you have? early with just the mfa mode button on stalk and 1/2 switch on clocks, or late with both the mode and 1/2 button on the stalk

Hi John. Thanks for getting back to me. It's definitely the later type on a 1990 Cab Gti. So if the clock is working, which it is, does that mean the earth is ok? I've owned the car for about twenty years and I think I'm the first to take the trouble and lose a lot of skin taking the instrument cluster out but couldn't get the multi pin connector off the back and panicked in case I damaged the foil circuits so put it all back!! Done loads in the distant past on Mk2 Sciroccos but that was in the days when you could pick up a cluster from the scrapyard for a tenner. Think I should go back and pull it out again and make sure the multi pin connector is ok?

2 ways to unplug the instruments.

Remove the cardboard above the pedals and you can get in behind the instrument to unplug stuff but it's not easy with the front seat in the way, makes this job easier if you remove the front seat.

If you have small hands it is possible to unplug the main plug into the instruments by pull them out a little.

start at the plug on your MFA stalk rather than pullignthe instruments On the car of the plug side the brown/white wire is the earth, touch that to the other 3 pins for mfa functions:
white/red - change mfa mode - main clock plug pin 8
black/white - change between memory 1 and 2 - 2 pin plug on the back of the clocks
red/white - hold to clear mfa memory - 2 pin plug on the back of the clocks

if no response run an earthed wire from chassis/earth claw/wherever and repeat the tests

why do they have a sensor on the gearbox
is it to read speed distance travelled or when
to change gear or upshift interested about the
gearbox sensor

The switch in the gearbox is for the reverse lights and to tell the cluster the car is in 5th. This disables the upshift light and switches on the not needle in the big gauge.

The speed signal comes from the back of the speedometer

do you have a image of
where the reverse light
location is on the gearbox

is that the one with two connections
not the 4 pin switch

The 2 pin one is reverse switch only, and won't work with the early MFA. For those you need the multi pin switch

Info here on multi switch for gearbox.

Reverse Wiring

hi Guys, then the mfa command works both 1/2, on the gearbox I don't have the bulb that indicates the arrow so I think it's the dashboard to have problems, the connections of the command mfa I think is right I have redone all the wiring of the new interior, lighthouse the test by immediately replacing the dashboard with a test one, for the moment I thank you

Thanks for the advice above Peeps. Going out to give it a go now.

Yes David82 the issue will be the cluster itself, either blue foil damage, speed sensor is dead or the speedometer itself is to blame.

1st check is to remove the clocks and check the blue foil for any obvious damage. if you flip the clocks forward with the wiring still plugged in you can check for ignition live across the live and earth pins on the speed sensor foil, its the 2 outer connections.

if you find the connections are all good you can test a new speedometer by putting something suitable into the back and spinning it manually, though you'll have to spin it over a thousand times to get it to register 1 mile on the distance setting

later type clocks have a secret MFA mode, if that works on yours put it on the speed sensor setting it should register 4 pulses for every rotation of the sensor
https://www.clubgti.com/forums/index.php?threads/how-to-access-the-mfa-secret-menu.219196/