Mk2 clocks in Mk1

Hi

I have fitted a set of mk2 clocks out of a jetta cli into my 1984 mk1 GTi. I followed the advice given in the topic under FAQ. The mk2 clocks have the dual plugs, one white and one black. I tested the clocks in my cli 16v and everything was working perfectly . After fitting them to the GTi however there seems to be a problem with the oil pressure light and the battery light . The battery light doesnt come on when you turn on the ignition, and neither does the oil pressure light flicker as it should. Everything else works as it should including the mfa. What is even stranger is that the oil light does start to flicker after the car is started. It does this regardless of whether the yellow wire is attached to the oil pressure sender on the side of the head or not. The sender unit works as I have tested it with a test light. When wiring in the new clocks, I kept the old connectors for the mk1 clocks, as I may want to swop back if I get the rev counter and odometer on the mk1 clocks working again. Plugging in the mk1 clocks again sees everything working properly as it should, battery ligt on, oil light flashing upon ignition, and both go out when the car is started. This isnt a problem I can simply ignore, as the buzzer kicks in now whenever I ride the car, it obviously doesnt detect oil pressure. 8O

I hope that someone may be able to offer some advice as to what may be wrong. :dontknow:

Thanks
WFC

Same happened to me, I used another set of clocks and it didn't happen again.

Although the oil buzzer on mine comes on at 2k, I intend to remove it as I run a pressure gauge anyway

It took me a long time to find this instrument cluster, and it was quite expensive, so I am very reluctant to start searching again. Surely there must be something that can be done?? Why does it work perfectly in my mk2?? Please guys if anyone out there has any ideas I would realy appreciate your input

Thanks

I wrote the 'how to' and have now carried out a few conversions as have loads of others using MK2 clocks . The only problem people have come up against is the lack of a seperate earth for the clocks . Have you earthed them ?

Was all the wiring correct as per the diagram ? I had afew problems with my latest project using MK2 clocks and had to [sorry this is pasted from old post]

 Few pointers for you , oil wires are yellow for low pressure and blue black high pressure . The high one is mounted on the filter head low on cylinder head . I fitted guages to my 20VT conversion so did not want the oil light or any MFA function etc on the dash except the digital clock , so did not connect the oil wires to the clocks and guess what buzzer and flashing oil light over 2000 rpm . Driving me mad .

This leads me to think that if the clocks are not getting the right signal they will buzz . So fitted the oil wires to the clocks and earthed the buggers under the dash , problem solved Cheesy Grin You could of course remove the buzzer and lamp if you wanted , but thats more work and may affect clock functions ?

So if you are happy to have 'NO' clock oil light simply earth both wires near the clocks and use separate guages . If you need MFA oil temp ? That should be fine as its the green black wire and not connected to the buzzer .

Hi Chudd

Firstly thanks for the "how to" on the clock change, without it I would never even have attempted this. As far as the wiring being correct, I followed the diagram, and everything seemed quite straight forward except that I had two black and two red wires, a set for each of the connectors. I gave both sets of red 12v, and both sets of black ignition.

I am from South Africa and have noticed that our cars and yours over there do have some subtle differences. For example ours dont have the earth on the rocker cover for the instruments. I did however earth the brown wire directly under the dash.

My yellow wire goes to a sender on the side of the head, and blue/black goes to a sender on the oil filter housing. I believe this to be correct as my other 1983 gti is wired the same.

Am I correct in understanding that the oil pressure causes the switches to simply earth internally and thereby send an earth to the clock on that wire? Would it then be the blue/black wire that is causing the buzzer to sound when driving, or could it be the yellow one as well?

The oil temp is registering fine on the mfa.
Thanks for your reply,

I have checked with a test light, and the two switches work as follows. The low pressure on the side of the head is earthed when the engine is switched off, and loses earth when it gets pressure.

The high pressure is open when the engine is off, and switches to earth when the engine is started. So it works the opposite way to the low pressure switch. Is this correct?

Also checked that earthing the yellow wire through test light when buzzer sounds over 2000 rpm does turn off the buzzer.

Am I correct in understanding that the oil pressure causes the switches to simply earth internally and thereby send an earth to the clock on that wire?

That's right  , that is why when you earth the sender wires the buzzer and light goes off   

This leads me to think that if the clocks are not getting the right signal they will buzz . So fitted the oil wires to the clocks and earthed the buggers under the dash , problem solved  You could of course remove the buzzer and lamp if you wanted , but that's more work and may affect clock functions ?

Try all the tests in this post ……

http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=19462

I remember reading about sender compatibility ? Might be worth thinking about .

Hi Chudd

Thanks for the help so far. I have managed to sort out both the oil warning light, and the buzzer problem :mrgreen: . After much confusion for a while I grabbed the testlight and began to see what exactly the clock wanted to see on the blue and yellow wires, and it turned out that it simply wanted to get the opposite inputs that I was providing 8O .

Instead of normally closed to earth on the yellow low pressure it wanted normally open, and instead of normally open on the blue/black high pressure it was looking for normally closed :dontknow: . Thus just swapping the wires around solved the problem. Now the oil pressure light flickers on when ignition comes on, and goes off when the engine starts as normal. The oil buzzer also doesnt sound above 2k as it was doing.  :clap:

This did trouble me though as I wasnt sure that it could be right, so I went over to my Cli16v and compared its factory standard wiring to what I had just done. It was wired in exactly the same way, with the yellow low pressure wire going to a white normaly open switch, and blue going to a normaly closed one.

As I said earlier on in the post, the clocks worked perfectly when I tested them in the 16v, obviously because the Mk2 16v has the switches fitted the opposite way to the Mk1

Thanks again for the help in understanding what should happen.

Nice one pleased your are sorted

Cheers ………………….

So then would this be a dumb question if I was to ask if the Early MK2 8V clocks would be spot on in my Mark 1 8V Gti...?

Yes mate very early MK2 with K-jet engine clocks will .

Sounds a bit confusing, so which two colour wires did you swap around? I will try this so I can stop the buzzing in mine!

chudd said

Yes mate very early MK2 with K-jet engine clocks will .

Cheers fella!

You can either just move the yellow wire (side of head) to where the blue wire went on top of oil filter housing, and then the blue to where the yellow went (side of head), alternatively you can simply join the blue wire to the yellow on the clocks, and the yellow to the blue on the clocks. Both will do the same thing, the busser will be quiet and the oil light will go off when the car is started.

basically the reason for the confusuion is that earlier mk1 and MK2 pressure sensor wires are switched. On the early MK1 blue is the high pressure sensor on the oil filter and yellow is the low pressure sensor on the head, on the MK2s the opposite is true.
Its the same on my 83 cabrio