Issue with dash cluster

Hello I'm new to this group and I am looking for some help please, this is my first mk1 golf so need someone to point me in the right direction, basically I bought this 1980 mk1 golf cabrio a few weeks ago and I am just ironing out a few little problems with her, since I bought the car the dash cluster has problems, the temp gauge works when it feels like it, the Rev counter is stuck at 7k rpm when ignition on and even when it's running, and also the oil light flashes with ignition on, the oil light sometimes flashes and makes a buzzing noise when driven, but the car has the right amount of oil in. These are them main issues I'm experiencing with the car. Help appreciated thanks. 

Sounds like the earth to the cluster is broken.

There should be an earth strap going to the corner of the rocker cover, if this is missing or broken then a lot of these issues will occur.

Briano1234  has a fix for this which I can never find! I'm sure he'll pop along and tell us where it is again

Ian

Here is the link to Briano1234 very helpful topics…

View topic: My DIY list of things for a 90ish Cabriolet (digifant2) part 1 - The Mk1 Golf Owners Club

Check the earths 1st.

The buzzer is a sensor for low/high oil pressure and only works when the engine is over 2000 rpm not for the amount of oil in the engine so either it's a faulty sensor, instruments or you have low oil pressure/faulty or blocked oil pump.
What oil are you using?

Why read all that when you could of posted:

Repairing your Flaky Water Temp Gauge | Volkswagen Owners Club Forum

Thank you for the help I'm going to check the earths and see if any are not connected or missing, and I'm not sure what oil is in her as I have not long bought the car and an oil change is on my to do list, owning a old Volkswagen is new to me as this is my first mk1 an I have owned 12 hondas before this so just getting used to it at the minute I'm confident at fixing cars just wanted some input before I start working on the clocks thank you. 

For an oil change buy a good quality filter, genuine VW or Mann are the best ones to get.

Oil filter (Euro will have discounts at some point, the last discount finished Monday)

https://www.eurocarparts.com/ecp/c/Volkswagen_Golf+Cabriolet_1.8_1988/p/car-parts/regular-service/car-service-parts/oil-filter/?501770059&1&df2e88f773d5c865f404b9dd795cf6fb0b433883&000231

Oil I've been using for a good few years. usally about £12 with discount at the right time.

https://www.eurocarparts.com/ecp/c/Volkswagen_Golf+Cabriolet_1.8_1988/p/car-accessories/engine-oils-and-car-fluids/engineoils/10w40-engine-oil/?521776011&0&cc5_245

Don't forget to fit a new sump plug washer.

https://www.eurocarparts.com/ecp/c/Volkswagen_Golf+Cabriolet_1.8_1988/p/car-parts/engine-parts1/engine-parts/sump-pans-and-sump-plug/?333771291&1&47c8751ced189bff5450784e05f1acd1b6276fd2&000567


Genuine VW filter
https://www.vwspares.co.uk/product_info.php?products_id=1179

Oil VW would use.
AVS Car Parts


12 months or 10,000 miles for oil change.   

Thank you I will be doing the oil change tomorrow this forum is so helpful really nice people on here unlike the Honda forums I've been on in the past . I've just checked the earths in the engine bay they are fine so I think the issue lies behind the cluster itself.

mk1gticabs said

I've just checked the earths in the engine bay they are fine so I think the issue lies behind the cluster itself.

Checking by look isn't a good thing, either a voltage drop test, is better, but to be honest, if the ends have been replaced, replace the cables.  If the cables are still OEM that is unshielded then replace them.  OEM cables still on the car are over 35 years old and probably not up to shape as corrosion can build up between the strands of the cable reducing the overall capacity to carry current correctly.  

Just saying as I have made a career of spurious ground faults or earthing issues on a wide variety of electrical things.

mk1gticabs said

Thank you I will be doing the oil change tomorrow this forum is so helpful really nice people on here unlike the Honda forums I've been on in the past . I've just checked the earths in the engine bay they are fine so I think the issue lies behind the cluster itself.

Yes we do try to help when we can..
 I do like a Honda, had a couple of Civic in the past, loved the 1992 1.6 B16a twin cam VTEC with 160ish bhp , and I deleted the CAT and bigger exhaust, bit of a wolf in sheeps clothing but you had to rev it to get the most out of it 5000rpm and off it went…. it was a 4 door Civic saloon which never went wrong,  you don't see many of those about about now…

Last Honda was a more sedate family car being a 2002 1.4 SE a small child arrived in my life so needed a cheap to run car which it was and again the Civic only ever needed servicing, we did about 80,000 miles in it!

Anyway back on to the Mk1 Golf.  

Ok I will have a proper test done tomorrow and I'm going to pull the clocks out and have a proper look and see what's up with them I've got an electrician in my family so I'll get him to give me a hand if I can't do it myself thank you for the help hopefully I can get to the bottom of what's causing the faults 

There's a good guide on here about removing the instrument cluster, I found I don't need to remove the steering wheel. Be carful with the blue plastic circuit board as it get old and fragile.

Found it.

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

There is a few different designs of instrument clusters, they look similar from the front but differ behind.

Thank you I will follow this guide when I remove the cluster, people are very helpful on here I like this forum 

I removed the clocks today to find the issue with the Rev counter, and it seems someone has put a wire on to the connector from the plug that goes into the back of the clocks to the alternator for some reason. I will upload pictures to show what I'm on about, I think this is the reason why they are not working properly.

Rev counter should get its signal from the coil....

Photobucket isn't working for me at the minute but I have found out the extra wire is for the battery light on the dash, think I'm just going to buy a new set of clocks

Photobucket does not work for posting on forums anymore unless you pay for it monthly.

Add images tab below if you have them on your computer or use the free tapatalk app on your phone and you can upload them from that app.

add them directly from puter to here or open a IMGUR account.

wondering what the outcome for this issue was as im experiencing something similar.

i have a 1988 gti kjet cabbi 1.8.

Went to give the ol girl a run out today as its the first nice day weve had this year.  Had previously had the tempreture light flashing so was planning on looking into the reason for it first.

Started up no problem, but as expected the temperature gauge went straight up and the light was flashing. Next thing i noticed was a strong smell of burning plastic and smoke coming from the heater vents and from under the bonnet right up against the bulk head. had a look around and found that the heater unit has seized  completely, and the switch on the dash for the rear heated window has melted at the back.

Disconnected the wiring to both, checked the fuses and neither had blown.

turned ignition on but didnt start it up and the temperature gauge goes straight up to max. Disconnected the sensors which had no effect.
re connected sensors and turned ignition on again, guage goes to half way, and stays there. Light also stops flashing, only now the lcd clock display has gone blank.

before i start pulling the dash apart, anyone with similar experience or advice?

Dave

Bad or flaky Temp Gauge, as you didn't state that the fuel gauge was "Acting up".

Why because there is a 10V stabilizer that the fuel and water gauge uses to keep the needles steady, if it was bad both gauges would act up.

There is also an issue with grounds to the cluster that you need to verify on the car that there is a Ground wire from the Valve cover to the Bracket that holds the coil.

You would also be better served by "Plumping" the connector on the bottom of the cluster to insure that you have better connectivity to the pins on the connector, I have also found that adding a "Frame Ground" on the wire side of the connector to the inner firewall a good thing…

As for the smoking things, I suspect that you may have fried your ground wire to the motor, it is very common to me, I have seen it on the 4 cabbies that I have owned.

On the left side of the heater box is a White or Yellow Molex connector, and on a/c equipped cars there is a 5 pin connection.  The Brown wire can get toasty…Burn and then you don't have a ground to the motor so the motor stops.

I have seen it smoke while the plastic connector melts.


This could also be a issue with corrosion on the nuts that hold the thing to the cluster so it wouldn't hurt you to validate that is is working by looking at the links above to diagnose or repair a flaky water gauge.

Electricity is funny, as current will find a way around things to make a connection, and it may not be the obvious path…. Ie: I have seen Starters use Sensors, clutch, and speedo cables to seek ground when the primary Earthing points are less than stellar, and the Speedo cables I have seen melt the clusters.

So Clean your earth connections batter to frame and frame to Engine/Tranny.

The heater Switches are high Current Positive voltage.  It switches the voltage in from the fuse box to different pieces of the Resistor for the motor.
The Grounds for the motor are isolated, and separate from the switch, they usually are tied to a "Star cluster" or the outer shell of the steering shaft tube.