HELP!!!

I'd appreciate very much your help in this problem in my 1984 Gti:

Sometimes, suddenly half of the dials go black out. Speed counter stops working as well as temp and petrol gauges and all the lights and indicators of the right side, etc. Left side continues working normally. It can last for five minutes or one hour, depends, but usually it comes to work as suddenly as it stops.
The main problem is that, while this is happening, the alternator stops working, so does not charge the battery. If the failure last enough time, the battery gets empty and the car stops at all. That has happened three or four times, and once stopped, need a spare battery to go on (can't start pushing the car as the battery is empty and gets no charge)

Any idea?
Thank you very much

Sounds like a broken earth strap but visual inspection and logical fault-finding would confirm this.

What do Divorces, Great coffee, and Electrics all have in Common……
























They all Start with Good grounds.

Strange the speedo stops working as that's run from a cable directly from the gearbox and does not have any electrical systems, do you mean the rev counter stops working?

Check for any water or damage on the fuse box, make sure the drain plugs are clear in the scuttle area underneath the bonnet.

Check you have 2 earths going to the back of the rocker cover, 1 bigger wire from the coil bracket and a thinner wire from the loom serving the dissy etc..

You are right: is the rev counter that stops, as well as all other electrical gauges and indicators. Obviously speedo keeps on working as is mechanic. Thank you very much.

Thank to all of you. I'll begin testing:

-fuse box
-possible jammed drain plugs
-earth straps and plugs

Does the clausor usually gives problems? Someone told me it could be the cause, but I'm not so sure…

Thanks again!

Take the fascia off remove clocks.
Clean the contacts on the blue ribbon. These contacts go into the multiplug on the loom.
Locate the plastic nib the ribbon folds over. Wrap couple turns of electoral insulation tape round the nib.
What this does is packs out the space between those contacts on the ribbon and the plug, therefore you get a better contact.
Lots of issues are caused by poor contact here.



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Forgot you’ll need to take the steering wheel off lol


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chortle said

Forgot you’ll need to take the steering wheel off lol


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I've not taken the steering wheel off the few times I've took my instruments out, it will give you more room if you do remove the wheel.

Guide here.

How to remove instrument cluster and replace illumination bulbs - The Mk1 Golf Owners Club


Picture… Instruments out and steering wheel attached….

if its got mfa clocks 1st thing to check is earth for clocks on the side of the head, its a brown/white wire with ring terminal.

Thank you very much indeed to all of you!
I do appreciate so much your help. It's not common in spanish forums to get such a complete info and help!

I'm afraid I'm having a big work ahead…

If your Fuel gauge, and water gauge semi tach stop working, then that is a sign that your 10V stabilizer is bad, it is a fa7810-aet (but at a electrics store for pennies, or from the dealer for 35 bucks.

It can also be a sign that your Battery in or your ground is wonky. (pin 14 and pin 2) 14 is Battery in, and 2 is ground (brown).
This is where plumping your connection up with a single piece of electrical tape on the plastic tongue of the cluster connector behind the mylar connector is a godsend and adding a ground splice on pin 2 directly to the frame works well.

There is also the possibility that your mylar is cracked, and you are missing either the 14V or ground to the cluster on the cluster side.

How to plump your Cluster connector for better contact at the pins. | Volkswagen Owners Club Forum

https://volkswagenownersclub.com/vw/showthread.php/60258-90ish-Cabriolet-Mylar-repair-for-10v-stabilizer.?p=531266#post531266

https://volkswagenownersclub.com/vw/showthread.php/32211-Repairing-your-Flaky-Water-Temp-Gauge

When you take your dash apart, you will discover that there are 2 bare wires on the hazards switch one is brown and itty bitty, one os blue and black that is 12V live and un-shielded.  If you take a piece of heat shrink and place that over the bare connector then you won't blow f19 on the fuse box, and disable your turns, the usual sign is that when yo turn the turns on your dash light only glows.



See the bare connectors that you short and take out f19? 



 

yep vw really should have shelled out the 0.00002(EUR-) for a plastic spade housing from the stocks bin!

Thank you very much to all of you!

At this time the car is at the garage. They`re checking everything you advised plus other connections and looms here and there.
We are also making the distribution and other minor service.
The car is having trouble with the gases at the Mot, so another thing to check.

Thanks to all of you.

Problem solved -for the moment-
I did everything you recommended, so I expect not to have further problems with the clocks.
The actual problem, though, was at the steering wheel column. We found a broken conector at the lock barrel, changed the lot and fixed!

By the way; Is your fuel pump noisy?. Mine is quite a lot, almost umbearable. My mechanic says "it is normal in these cars"

the fuel pump should not be that noisy. if it is, this points to cheap pump, poor fuel supply to pump, or pump is just about to die.

if its a post-84, there should be a lift pump inside the fuel tank, which feeds a fuel reservoir under the car, which then feeds the main pump. top suspect for noisy main pump is a failed lift pump!

It is actually a 1984 car (october or november).
The sound comes form the right rear part of the car, like from under the rear seat. The seller told me the car had two fuel pumps, so it must be that you say.
Thanks again.

how I do it:

https://volkswagenownersclub.com/vw/showthread.php/32212-1984.5-1993-mk1-How-to-change-your-in-tank-fuel-pump

Thank you very much. I've decided to change both pumps, as they are not expensive and doesn't seem to be a difficult task.

Lift pump is straight forward, the main pump underneath the car is a right pain and I would leave well alone if it's ok, the connection can rust as it's exposed to the elements and it's not easy undoing them.

Main pump buy a good quality Bosch pump, about £100 for a new pump if replacing that one as well but 9 times out of 10 it's the lift pump which fails.