economy gauge & MFA

The needle on my economy gauge does not move although the light comes on when i need to change gear also the MPG reading on my MFA reads 99.9 all the time even on a long run, any ideas on whats wrong & does anyone think they are linked somehow, (its an '84 cabby)

could be the relay,whichhas  number 5 on it?i swapped mine today and mpg is working ok but the yellow light and gauge still don`t work :dontknow:

Thanks, is there another relay on the car i can swap it with just to try, someone also told me that the gauge has a plastic air tube attached at the back of the dash which sometimes comes away (this may be the fault with yours) but i only want to remove the dash as a last resort

no i don`t think so.ive had my clocks off and on a number of times recently to get the lcd display working(swapped it from another set) and the pipe is connected.think there is a transistor in the thing you attach the pipe to,that might be the prob.
if anyone reading this can advise??

you need to remove the knee tray under the steering wheel and get your hand in behind the clocks to see if the pipe is attached,its only thin,comes from the vacuum pump attached to the dizzy

 removing the clocks 1st time around is fine,its putting everything back thats a nightmare  

Ok, thanks for your help

You could try here in FAQ's…

http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=29534

If the 5 pages or so are enough, have another look in the FAQ section at the bottom of ther forum because this subject comes up time and again.

Dan

Thats great, thanks Dan

If the pipe is off at the back of the dash you'll hear a blowing/sucking noise which is very noticable.

Ok, i will remove the dash & have a look, as i doubt i will be able to hear the sucking/blowing noise as its a cabby & the roof isnt the best fit in the world,

Many thanks for your help,

The needle only moves when you are in fifth gear.
More than likely the connector on top of the gearbox is crudded up, so that the dash unit never knows fifth is selected

any idea where the connection is on the gear box?

bamba said

any idea where the connection is on the gear box?

Part of this part in this post https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=electrical-faq_2%2Fgsf-reversing-switch_2

Good luck , your gear linkage maybe to blame if it is not adjusted correctly you will never switch the 5th gear switch if it is . Try a fiddle with the gear stick [gently] while on the move , push pull etc , the econ guage should rise .