VDO gauge needle shooting strait up to maximum, fixed now

As said in the title.

WHY are my 2 gauges oil temp and oil pressure when ignition turned on going STRAIGHT up to maximum??

ive been trying to sort this for weeks now, i tried what i think is everything.

as soon as power goes to it they work

please help

Ok mate I had that problem when I put VDO's in mine.They don't seem to work the same as the smiths type gauges,I'll have to dubble check mine but from what I can remember you have an ignition live,one to the sender and one to earth.I know on some of them which is which is not that clearly marked.I think 1 is live 0 is earth and the other goes to the sender.Those oil pressure senders can also be tempramental some times so don't rule that out completly.
Best of luck anyway
                                        Baller

hi, thanks for the reply but whats really annoying is that its all in the right places, these are marked ok with + and - and the one from the sender, its a brand new oil sender i have two of them , after one went faulty.
also a water temp thats doing the same, stil stuck for ideas….

bump

My TD done this when i put the engine in and tried to start it,it was the engine earth from gearbox to chassis,also check the earths from the clocks to the body.
Bert

Not sure if you received wiring diagram for VOLTAGE/OIL PRESS gauges (VDO typpe) from me - if not, PM me your emaill address and I'll send you copies - might help (note - DON'T have OIL TEMP)

 :wink:

hi bert i will check that again i have even tried doing it direct from battery earth to positive and feed and it still did it then even before i installed it.
bytor i will PM you now and see, thanks.

By sheer chance, I have this same problem too. I think its caused by raised engine earth, resulting in the 'reversal' of the current in the gauge and the effect you observe. I too had an earth strap issue, in the end caused by using a powder-coated gearbox mount. Its pretty easy to detect - your starter motor doesn't turn! I have replaced my earth strap but I haven't reconnected the instruments to see if they're fixed too.

Bert said

My TD done this when i put the engine in and tried to start it,it was the engine earth from gearbox to chassis,also check the earths from the clocks to the body.
Bert

my earth is fine, everything else works, i know its ok as i tried it with the + and neg from the stereo to see if it would work and it does, also wired strait to the battery neg aswell. i dont have any problem with geneeral grounding, also just had a new earth strap fitted to mine aswell as the old one came lose or broke off and thats when the car didnt work, but its been 6 months since then.
Im stil pretty sure its not the earth doing this.
let me know paul if its that for u

Today i went out and made sure all the connections are ok, i used the MAIN ground this time for all the electrics by the fusebox, found a spare space.
I used a multimeter to test proper 12v is coming through on it and it is, so thats fine, tested for any breaks in the cable and none.
So as soon as the 12v gets eathed it shoots up to max on both gauges still.
even the meter says everything should be fine so why isnt it…
the two gauges im trying to get working are
oil temp and
water temp

Check the resistance in the wire from the sender with your multimeter.  IIRC you should have 200-300 Ohms from cold engine. Could be a duff sender.

hey thanks also i did that yesterday.
will check again later on.
i also have a spare sender that i could try too.
both senders are brand new but i realise that it could be broken anyway.
but even withought the sender cable on when + and - are on the gauge it still does it straight away again,
wether the signal wire is on or not.

it doesnt make sence.
well i hope this thread will help someone else out that has the same problem in the future if they read this.

literally did everything yesterday on my day off

For info, mine are now fixed. I corrected 3 electrical problems, I don't know how related they are though:

1. Poor earth between engine and battery - which also affected starting
2. 2 'crossed' wires on the wiper motor wiring (I have a Mk2 upgrade, so my wiper motor wires don't have a plug, just 5x spade connectors which go into the original terminal on the car). This was causing fuse 11 to continuously blow
3. Some wires were inadvertently draped over the exhaust manifold and had partially melted.

Also, for info, when either the +12V or "gauge" wire on the oil pressure gauge was connected (but not at the same time, eg only one connection) the gauge jumped to off-scale beyond 10 bar. But with both connections, all ok.

hi paul, thanks for that.
i have all 3 brand new cables in the car and i metered them to check none are damaged.
glad yours are all working.
maybe could you take a pic of your sender if you can? if not dont worry.
thats all im beggining to think it might be?! as everything else i have tried.
Also yes i do have the mk2 wiper motor in mine too but seem to have no problem with crossed wires or fuses blowing.

so i must carry on until this is done.
its strange that with all the connections its all ok.but not withought, when all mine are ok and it still does it.
Must be the sender one, as 12v and - feeds are fine.

My oil pressure sender is the type with 2 terminals, one is the low oil pressure switch (since it replaces a plain old oil pressure switch) and the other is the gauge sender. Its now so awkwardly positioned, its not possible to tell which one is which!

The oil pressure sender is on the oil filter housing, the one at the front, further from the engine is the 'low' one (0.5 bar) and the one nearer the engine is the 'high' one - 1.8 bar. My gauge sender is 0.5 bar switch/10 bar gauge, so it replaced the 'low' sender. The oil temperature sender (on a 16V motor) is at the back on the left, above the exhaust manifold and has a flat circular connector which a female spade can be pushed on to.

I have these pics:





1 is the 'low' (0.5 bar) oil pressure
2 is the 'high' (1.8 bar) oil pressure
3 is the oil temperature

My gauge sender is fitted in place of the switch in 1.

Been out doing some tests on the oil pressure gauge.If I take the wire of the transmitter on the engine so it is now floating in mid air doing nothing,Turn the ignition on and the gauge goes off the scale.Put the transmitter wire to earth and the gauge goes back to just registering [where it should be with the engine switched off.]
You could try putting the transmitter wire to earth on your car to see what happens?
I'm sure between us we will get there in the end. Best of luck

         Baller

well hello again baller and paul
thanks both for your input with this.
Paul i will try that right now! thats something i havent tried.
i have tried 3 different senders today so i think its safe to say its not that either, must be where its placed.
well back out now ill try again. will let u know in a bit.

NB: my oil pressure plate thing has 3 senders on! im taking the front right one out to try this swapping over the senders so it could be that.

ok well another update, i have done what both of you said and it doesnt seem to jump to max anymore!
i dont know if it will move at all until i go out and get it warm which is what im going to go do now.
Here are the pics of what i have done.

1st: being the piggyback crimp i used to keep exisiting one (probably for MFA?) and also the new green wire feed going to the gauge.

2nd: is the 3 sender unit i have at the front of my 16v rather than the two one that paul has? dont know what the difference is. but heres a pic to show. I have just used an old sender from mk1 8v that i had before to fill in the hole as i cant find the proper one that came with the engine.

3rd: is the water pipe going into the side of the engine, i have a water gauge and once again dont know where that goes. looked in haynes that i own but i cant see it, i know its probably in there somewhere but i have no idea where. is it either of those?

Well i hope its finally over and done i will let you know how it goes later.

That makes sense. The pic 1 is for oil temperature. Pic 2 has 2 low & 1 high oil pressure points, one of the holes is sometimes used for oil temp too. On a 16V, the ECU has a connecton to know water temperature too.

Why did you need to piggyback 2 connections onto oil temperature, are you running a VDO gauge AND MFA (which has oil temp)?

I guess you're into decoding the colours of the wires and tracing it through the wiring diagrams. If it helps, I have a Mk2 Golf manual in PDF form, with a bunch of wiring diagrams in it.

yeah i wantedd to keep the mfa working aswell as the vdo gauges too, as the gauge says 60 then the next marker is blank then 130. So would like to keep another watch on the figures.
Well this mfa hadnt worked anyway after the test it stayed on - - - while the gauge worked perfectly! thanks alot for all your help by the way been doing this for weeks and weeks.
The temp seems to be much higher than the one on the mfa for some reason though?
the mfa would always show 91 ish when warm, but vdo temp shows very close to 130 on the gauge.
Is this becuase its attached to the head now?  and making a much higher temp? and being near the exhuast manifold? i guess that would make sence.
In that case i always know what to use the other one on the oil cooler for now if i get a pressure gauge back.

so yes now just working on the water temp, oh i just realised what you wrote, i have the pdf file of the mk2 manual i downloaded it but thankyou very much for offering, i spent a while looking for it a few weeks back.
Im not sure about the colour coding or where to go as the engine wasnt installed by me i took it to a garage to get the work done and i dont know if they would have kept to the right colour code or not.
So i dont know how to tell where they go.
There is alot of bright colours used so a bit confused.

bet you cant wait to get yours up and running. Very close now i read, well done, admire you done it yourself.