Vcds test

[twoqu]

The clue is in the word 'states' rather than illustrates!
And thats the factory documentation. Page 13.

[UrS4boy]

The clue is in the word 'states' rather than illustrates!
And thats the factory documentation. Page 13.

Sorry. Still missing your point. (But don't bother)

[bilko0795]

Dave I have taken a photo of the S fuses but there is no S27 fuse with the others it must be somewhere else under all the spaghetti do you know where it would be ?

[twoqu]

S27 is one of the two fuses under the red MOTOR cover in the fuse box which a few posts ago you said had 3.65V on!
It should have one thick Red wire on one side of it.

[UrS4boy]

Dave I have taken a photo of the S fuses but there is no S27 fuse with the others it must be somewhere else under all the spaghetti do you know where it would be ?

Sorry but *IF* we are going to help you, *YOU* have to pay attention to the information that we provide you here. I posted this photo on Page 1, Post 7 of this thread, 3 pages ago. Can you see the "27" (and "24")??

[bilko0795]

Sorry but *IF* we are going to help you, *YOU* have to pay attention to the information that we provide you here. I posted this photo on Page 1, Post 7 of this thread, 3 pages ago. Can you see the "27" (and "24")??

A bit of confusion on my part the picky you posted showing the fuses with a S26 5amp fuse I'm under the dash and my son is reading the post and telling me there should be a 5amp fuse so I'm looking for one. Over the w/end I will endeavour to read and try to understand all that has been advised and hopefully resolve this problem.

[twoqu]

Just concentrate on S24 in the fuse box. Measure for voltage on both sides of the fuse, ideally the wiring either side to confirm that power is coming in from the fuel pump relay and out from the fuse. If you have power in and out but none at any of the common components its likely you have a issue with the wiring, perhaps a broken wire before the crimp with the other wires in the harness itself.
You can confirm this by checking for continuity between the fuse and the power feed for the component. If its open circuit there is a break in the wiring. You could also test between the power feeds of the components. If they are are closed circuit then the break is before the crimp. Its just a process of elimination!

[UrS4boy]

A bit of confusion on my part the picky you posted showing the fuses with a S26 5amp fuse I'm under the dash and my son is reading the post and telling me there should be a 5amp fuse so I'm looking for one. Over the w/end I will endeavour to read and try to understand all that has been advised and hopefully resolve this problem.

Sorry if there was confusion but I won't take the full blame. The "S26" above the ECU is shown on a diagram clearly labeled as being for the UrS4/S6 Motronic ECU. That diagram was in the same post (Post 7, pg.1 of this thread) that clearly showed the S2/RS2 fuse arrangements with the S2/RS2 S26 in the main fuse box, away from the S2/RS2 ECU.

Hope you get it sorted. As Robin (twoqu) said and I have also suggested, concentrate on *your* S24 and make sure that you have power into and out of the S24.

The original potential "source" of the "confusion" (if you don't read the label in the upper left corner):



Another potential source of S26 confusion (IF you don't read the label in the upper right of the photo) (photo was to illiustrate the nature of the wires going into and out of the fuse holders).

[bilko0795]

Right so far I checked fuse 24 and there is power. I then checked for continuity and it showed 0.58 I then checked the three plugs for continuity and don't know if I have done this right but I placed the ground probe to ground and checked the power to each plug nothing showing I then checked the other wire's that go to the ecu and the only one that showed anything was the wire on the N80 to the ECU which also showed ground to short on the vcds test I did again today. The figure was fluctuating between 13.40 to 14.23 on the wire from N80 to the ECU. I will start looking tomorrow for any corrosion on the fuse box as I remember when we had the really bad rain water dripping on my right foot so wondering if corrosion is the culprit on the wiring below the fuse box.

[twoqu]

Checking for continuity is basically testing a circuit to see if its all connected. Effectively its the same as touching the two MM probes together. The MM must be set to OHMs say 2K. Try it for yourself. Set the reading scale to Ohms the Omega symbol and then touch the two probes together. The MM should read close to/or 0. That means it is a closed circuit. Seperate the probes and it reads 1 which means open circuit.
So to test say the Wgfv, set the MM to Ohms, place one probe on the power supply terminal of the wgfv and the other probe on the S24 fuse. Doesen't matter if the engine is running or not as we are testing to see whether the circuit is intact. Do the same for the other components.
Not clear what you have checked for continuity or what the reading you have posted is as if its volts you haven't tested for continuity and if its an Ohms reading it will depend on the scale used for measurement.
We have asked previously if you are familiar with basic automotive electrical testing, which is what we are trying to achieve. We need to establish whether there is power out of the fuse and not at the components. If thats the case we need to know whether the circuit is still intact which is where the continuity test comes in.
So once again, is there power in and out of the fuse with the engine running?
If so, is there power at any/all of the components?
If there is no power at any/all of the components, which of them still has continuity back to the fuse.
It should take less time to test them then me typing this out!
Without that basic info we cannot help.

[UrS4boy]

...So to test say the Wgfv, set the MM to Ohms, place one probe on the power supply terminal of the wgfv and the other probe on the S24 fuse. Doesen't matter if the engine is running or not as we are testing to see whether the circuit is intact. Do the same for the other components.

And by S24 fuse, you mean the output side of the S24 fuse holder, i.e. the female spade pin that has the blue/red wire attached to it (not the green/black wire)

[twoqu]

Well if he has double checked the fuse as previously suggested then its isn't going to make a difference. The fuse is the obvious culprit when common fused components have no power. Thats why we are trying to ascertain whether there is power on both sides. He would still have power on one side if the fuse was blown from the fuel pump relay.

[UrS4boy]

Well if he has double checked the fuse as previously suggested then its isn't going to make a difference. The fuse is the obvious culprit when common fused components have no power. Thats why we are trying to ascertain whether there is power on both sides. He would still have power on one side if the fuse was blown from the fuel pump relay.

Let's face it, if you or I (or both of us) were on the ground, beside bilko0795, coaching him and his son, this would have been solved long ago. It's often difficult to communicate diagnostics remotely and expect easy peasy results.

[bilko0795]

UPDATE ON THIS ISSUE

All sorted it was a blown fuse all along, because of my dicky mince pies I missed the crack in the wire in what I thought was fuse 23 and not 24 so I also got the fuses mixed up So to fix this fuse cost me £40 for an auto electrition to tell me it was a fuse I feel a right t-t but in my de-fence I am getting old . He also told me my battery needs re- placing its only 2yrs old and it's a Bosch S4 thought I would get more mileage out of it ah well at least it's running ok now.

I think a lesson learned pay more attention to what is explained to me by the people on here I.e Dave urs4 and twoqu and I would have had this sorted weeks ago

Thanks lads For your input

[UrS4boy]

"dickey minced pies" - had to think about that one for a moment, thought you were telling us "porkies".

At least it got fixed an Twoqu (Robin) and I don't have to twist our brains inside out to figure out why it wasn't the fuse.