Dash apart...abit of help wanteded

Ok, so i took my gti cab dash apart to sort some little problems - no heater fan, heated rear window and no mfa readout. Whilst in there i have found a few things i want some help with

a) there is nothing to connect the mpg guage to…what do i need to reconnect it?




b) i found this not connected to anything…what's it for? :






c) on the back of the speedo/rev counter there is a little brass needle thing screwed in, about 2 inches to left looks like a place for another to go but it's missing. Is this anything to do with earthing the mfa….if not is it important and what is it for? Sorry the pics a bit blurred.




Managed to sort the fan heater now just need to sort the mfa which just glows occasionally but doesn't show figures or info. Also where is the earthing for the heated rear window?

Sorry for the essay!  ops:

earth for the rear window is in the boot, take out the parcel shelf and follow the wires, common to see them break.

What year is your cab mate?
If the dash has an economy needle and change up light then your's should be a cab from the early 80's?

There should be a vacuum pipe running from the engine bay to the back of the clocks. There should be one found running from here…



The 3 pin electrical connector is an odd one. Does it look aftermarket or original, if you trace the wires where does it go? Into an original wiring loom or where? It does seem very slightly familliar so it might only be found on early cars? I havent looked at my '83 GTI's dash wiring for years so I cant really help. My guess is its aftermarket though!

The earth for the MFA is a brown and white wire that connects to the rocker cover on the engine. Not quite sure how it ends up earthing the MFA but I know it wont be connected to what you have shown in the pics. It'll be in one of the main wiring connectors to the clocks. I think it might actually connect to the memory selector of the MFA first.
Those brass things you have in the pics are just electrical connectors for gauges to the printed circuit board. They are probably fine.

Have you checked the fuse for the heated rear window?

Cheers,

Ross

Yeah i've checked the fuse and it's fine. The light on the switch does flicker unless held down but even then it does not work?

I've seen that pipe in the engine bay….will trace it tomorrow. Thanks

THe wires to the 3pinhad been tapped back out the way...it seemed to go behind the carpet????

OK sorted the rear heated window-ish A few of the lines demist but not many - some1 told me youcould get a pen to fill in the lost elements on the window. Where can you get 1 from?

Found the pipe to the econometer but it still doesn't work….is that linked to the mfa cos i still haven't got that to work? I checked the mfa earth was connected to the rocker cover, it is but it's not sitting on bare metal - is that needed for earthing of it?

My Cabrio has dealer fitted elecy windows and central locking that uses connectors similar to the 3 pin jobbies.

b), the 3 pin plug, is the connector for the rear speakers to a dash-mounted fader, if fitted. If you have a stereo stereo, using the 3 wires instead of 4 will make the sound go funny.

Cool jools….what can i do to sort my mfa then? Double checked the rocker earthing point and it it's good and clean. Is there anything else to check for it?

Have a look under electriocs - "MFA and 99.9 mpg" - there is a photo of where to connect the econo-meter vacuum tube to the back of the instrument panel - for one type of instrument panel

Then have a look at "Hall Sender and 99.9mpg" - there is a plethora of infortmation on the MFA, how it connects, its inputs and so forth  pluis further photographs of how to connect the vacuum tube for other types of instrument panels - they regularly changed - and there was a makor design change 1983 - 1985.

Then have a look at "Change Indicator and the econo-meter" and most of the the information (if not all the information) you should need on how this hooks up is available.

A key point to check first is the MFA earth which is the brown wire that connects to the rear right hand corner of the rocker cover - there are numerous photographs of this wire under the Electrics section so have a dig about.  It is worthg taking this earth off and cleraning it up with emery paper to make sure it has a solid connection.

Michael.