electrical problem.. please help!

[nhop10]

i have recently bought a mk3 golf gti 8v and theres a few elcetrical problems that i have no idea what is the problem.

firstly i noticed the problem when seeing that when turning the engine off and taking the keys out the clock needles had all stayed where they were (so rpm at 900, temp and oil guages at what they were)
every time i come to the car and start it the clocks seem to reset themselves, by making a clicking noise, the needles going back down to zero after kinda twitching and then they work fine after a few seconds, the clock always starts at 12.00 whenever i start the car again. the clocks work fine while driving.

other issues which i am unsure if they are linked is the fact the the central locking doesnt work, neither do the interior lights, cigarette lighter and the head unit thats in there doesnt hold presets after taking the keys of the ignition.? although when putting a different head unit in there it only worked when the ignition was turned on then off. as soon as the car was on or ignition on it didnt work? however all the leccy windows, mirrors air con etc work fine..

i tried reconnecting the earth but had no effect and bascially i dont know where the problem lays any help greatly appreciated!

[itavaltalainen]

which year and engine code?
stupid question but are the fuses all ok?

RE head unit, swap yellow and red wire around, most stereo's have plugs that allow you to do that without taking pins out the wiring, otherwise unclip from wiring harness in car and swap around (coulours mentioned are on the radio lead, vw colours would be red-white and brown-red). This is isolated from your other issues.

The reason why the clocks stay where they are is because you probaly have a later mk3 - with actuators / stepper motors, i.e. they are not returned to position by a spring but electrically. This could be caused by a problem with your ignition switch (or speedo itself).
How does central locking not work? Is it an original one - those are pneumatic... Do you hear the pump come on at all? Interior lights not working at all (I mean can you switch them on by hand?) or do they just not come on when you open the door? Then it could be broken wires in the door sill, just pull the rubber hose between the door hinges off and have a look. Also check the ground connection of the vacuum pump in the boot, it's where your spare is.

How is the ground connection from battery to chassis looking? Is the alternator running OK - what voltages do you have at battery with engine off, during starting and with engine running?

[Jamin]

I have exactly the same problem with my mk3 16v. I changed the fuse and it was fine for a few days but then it went again. Still trying to find out what the problem is.

[nhop10]

cheers for the reply mate!

the fuse for the clocks, interior light etc was blown, so replaced but it blew it again twice. there were some sparks coming from behind the the dash somewhere as a bit of a fuse got stuck in there but got that out. need to have a look behind the dash where the sparks were coming from, as something might be screwed up.. there was also some weird kill switch down by the fuse box, but didnt seemed to do anything?! wil have to wait and see. might need someone to check properly

regarding the stereo i will have another look at the cables and see if that solves it. fingers crossed

i do have a later mk3, 97 one so yeh its all electrical. i thought about trying a new pair of clocks but will try and solve the other problems first then i can be sure its the clocks or the not linked atleast.

the ground connection to the chassis was the first thing i checked and re did, although ill have a looksy at the boot one.

nothing happens with the central locking i dont think. i cant remember hearing anything when i turn the key.?

[nhop10]

ive just had a good play around with the stereo wires. i tried swapping the power leads over, they were the wrong way around but didn't make a difference and worked the same as before, but atleast now theyre correct according to http://www.installdr.com/Harnesses/VW-Wiring.pdf . got a voltmeter tester thing. the battery power lead (red/white - VW) stays at a constant 12v and works as it should. the ignition lead (brown/red - vw) is at 12v until i turn the ignition on at which point it it falls to 0! when i turn the ignition off again power comes back and the stereo works.

i tried to solve this by using the cable for the electric aerial (seeing as i dont have one) that measured at just under 12v but as soon as you connect the stereo to it the power drops to around 4 and the stereo doesnt work. still stuck! whats the problem? how do i get the 12v ignition lead to have power the whole time?!?! the earth seemed fine at the head unit. what would happen if i connect the ignition lead from the head unit to the working 12v battery lead already powering the unit??

the central locking i am still also stuck with and dont know what to do about. it doesnt make any noise when i turn the key either way..

[itavaltalainen]

Radio sounds like a problem with your ignition switch (brown red comes of the S contact). that could also be responsible for some of the other stuff.
As for the antenna lead, don't use that to power your head unit... not a good idea - there is a reason why it drops to 4v

How did you measure that the brown red is 12V with ignition off? Also you don't want to connect both to permanent 12v supply, there's a reason for there being two separate lines (i.e. radio drawing higher current with both being connected => will suck your battery empty over time).

Regarding the c/locking; what have you checked so far? any broken wires between the door and body? just pull the rubber back. also check connections at the c/l pump in the boot, this is either in the spare wheel bay (space saver wheel) or in the right boot cover behind the rear wheel (if you have a full size spare).

if you send me a PM with your email i can send you a wiring diagram. you can then test if signals get to the pump etc. my guess is either broken wire in the door or the corroded PCB on the c/l pump.

[nhop10]

i measured the 12v on the brown by just touching one of the connections with the measuring device pin things with the positive and the negative on the earth connection cable. i also thought that there would be a reason for having two separate leads hence why i didnt do it.

Whats needed to change the ignition switch? will i need a new barrel and key? bit of a novice so dont really a clue about things like that?

i havent checked much if im honest with the central locking, have just been focusing on a few other bits and bobs. nhopkins6@hotmail.com is my email so any info would be pleasently accepted. cheers

[Jamin]

On mine it was the blown fuse that caused the central locking not work.