whats this

could anyone tell me is this wiring in the picture coming from the gearbox how it should be or is there some wiring missing. just under header tank is a male multiplug with nothing to connect to aswell . the reversing lights and mfa dont work but if you put car in reverse with ignition on the black wire from gearbox is live and it runs through bulkhead into the car.its a 1990 gti cab any help please   
                  
    click photos to enlarge

anyone out there got a 1990 gti cab who can have a look to c if theyve got the same amount of wires coming from gearbox and a multiplug under headertank not connected to anything. c previous thread for pics

My 8v has that plug hanging under the tank doing nothing …..but you should have 4 wires [if you have an MFA] to that gear box plug

You should be able to take a note of the wire colurs and cross match them with Haynes manual .

Cheers……

thanks for that ive got mfa and that dosnt work nor do reversing lights where should they connect to any idea i have haynes manual but carnt work it out  

I think you'll find that gearbox isn't the original as gearboxes witht hat plug are only usually found on early cars where there is a change up light on the dash and an econometer gauge.

The wires to it are probably wired to your reverse light circuit in the engine bay. They look like they are the correct colour for the reverse lights. Black and Black/Blue.

The other connector… you do get the odd spare connector hanging about in the bay on some models.

Whats wrong with the MFA? the fact you have a different gearbox won't effect the MFA. Is the brown and white earth wire connected to the rocker cover? This is the earth for the dash and you get loads of problems if its not connected.

so the gearbox wires are ok then there must be a break somewhere in the circuit will have to investigate. read some threads on here concerning the mfa and thats why i thought the wires were missing from gearbox switch and checked all earthing connections in engine bay and they all seem ok what else could it be

What are the problems you are getting with the MFA? Is the LCD showing anything at all? of is it that you cant switch between modes?

Have you checked fuse 15? This is for the reversing lights. Also have you checked the earths in the boot?

mfa isnt working atall and fuse for reversing lights is ok. i will check the earths in the boot and trace the earth of the rocker cover to make sure its not broken. i will keep u posted

sorted the reversing light problem its the switch thats faulty so big thanks to everyone for the  info. not sorted the mfa though still dosnt work traced the brown/white wire from rocker cover it connects to dash loom at back of fuse box so any more ideas as to what it could be

Have you tried connecting the reverse wires to different terminals on the gearbox plug? It you wire it up wrong you might get the lights coming on in fifth gear instead!

I dont think the brown and white wire goes near the fusebox, it goes behind the clocks somewhere. I think it connects to the MFA switch on the stalk but changes colour first to white at a connector thats cable tied to the underside of the steering column. Not sure though.
The clocks themselves may have a fault somewhere?