A little help identifying the following earth points (pics included)

[SimonClarke]

Before I begin, I am a rookie and don't know a lot about cars at all.

Below is an image of the Electrical Diagram for the Instrument Cluster on my 1.3 Felicia (click to enlarge)

Everything up to and including contact point "u" works ok but "v" through "z" does not work (coolant temp gauge, voltage stabiliser?, rev counter, fuel guage, fuel low warning light).

I wanted to remove the instrument panel and get a look in underneath at the wiring but fell short at removing the Steering Wheel's retaining nut as I didn't have the adequate tool with me so that will have to be done another time.

In the meantime, I removed the lower shroud from the steering column to see if I could locate the E5 Earth Point in case that was the culprit. However when I removed the shroud I was met with the following view..

As far as I can see, it looks like there are 2 earth points here (arrowed).

Have I identified these as Earth points correct? I could get in at the one on the left which looked in fairly good condition but i gave it a cleaning anyway. However the one on the right appears to have several brown wires with connectors attached to it and it is not easily accessible to me with the cheap spanner/wrench combos that I use.

My questions, which of those earth points is point E5 as is described in Haynes as being "Next to `Steering Column" because both of those seem to fit that description, and is it normal to have only one connector on one side and at least 4 on the other side? A closer view of both points can be seen below..

Left Side of Column

Right Side of Column

[TeflonTom]

Don't quote me on this, I would have to check the skoda factory diagrams to confirm, but I think the one on the left of the steering column is for the heater loom.

anyway, before you go pulling all the wires out, firstly does the car have abs? I think it's more likely to be a dodgy instrument cluster than a wiring problem, all the internal busses and functions share a common ground/earth, they also share a common live feed however the the live feed is dependent on the ignition switch position

As a matter of interest does you brake fluid level warning light stay on permanently?

[SimonClarke]

I should have added that when the car has been running for a little while, the control buttons on the panel in the center of the dash are pretty hot to touch even when the blower is not on. This makes me think it's a wiring issue underneath.

TBH i'm not actually sure if we have ABS, herself does all the driving, I'm AD prone.

No the brake fluid level warning light does not stay on permanently nor does it come on unless the fluid is actually low.

[TeflonTom]

Ah ok.. Hot not good, what voltage are you getting from the alternator when the engine is running?

[SimonClarke]

13.9/14.1 while running.. I only changed the regulator about a year ago..

Edited 21 April, 2013 by SimonClarke

[adurer]

First of all, congratulations on photos quality. Well lit, superb focus, good resolution.

Now about the wiring problem. Devices 'v to z' are indeed sharing the same ground, but more importantly they have something else in common. Device w is a voltage stabilizer located on PCB for dashboard, and if I remember correctly the output is 8 Volts needed to feed stable voltage to fuel gauge y, rev. counter x and coolant temp. gauge v. The voltage stabilizer is using a simple 3-pin LM2940T chip and If you're interested I can help you trace if it's fried and replace it.

I doubt very much there's a wire loose going to earth point near steering column, or the earth point itself is bad. By the way, E5 is an earth point location designator referring to steering column vicinity. The wiring loom behind dash panel has 3 groups of ground wires connected near steering column. On Felicia wiring, the electrical connections to ground location E5 are marked as 42 in a circle.

About central dash buttons being hot: the only 'heating' elements near them are the bulbs inside. Are they hot too with all lights off after you let them cool?

Edited 22 April, 2013 by adurer

[SimonClarke]

Thanks for the reply adurer,

I have only noticed the central dash buttons being hot while we are driving and we always drive with the lights on.

Regarding the voltage stabilizer, I have a multimeter but have limited knowledge on how to use it. How will I determine if the stabilizer has the issue? Will it be a visual defect or will I have to connect some cables to it?

[Jonesy92]

Mine are always pretty hot to the touch, although I most often drive with the the sidelights and fog lights on for visibility.

I'll be keeping a beady eye on this thread with interest as I've some strange electrical issues (or so I've convinced myself anyway) that I just can't put my finger on.

[adurer]

Regarding the voltage stabilizer, I have a multimeter but have limited knowledge on how to use it. How will I determine if the stabilizer has the issue? Will it be a visual defect or will I have to connect some cables to it?

well, if you bought a multimeter, you did it to measure stuff, not to check for defects visually.Of course sometimes electrical components can explode or burn, but most often you have to rely on measuring voltages or resistance.

But before that, just to doublecheck, you have no indication whatsoever on coolant temp. gauge, fuel gauge, and rev. counter?

[adurer]

That is our voltage stabilizer. We'll have to check voltage on pin 5 of the yellow connector (blue wire).

[SimonClarke]

That's correct, there is no indication whatsoever on coolant temp. gauge, fuel gauge, and rev. counter.

I'm heading out now to fit a new headlamp (2nd time this one has blown in 1 year) and have a look at the PCB.. Back in a bit.

[adurer]

Take some nice photos of PCB while you look at it.

[SimonClarke]

Yes i took a lot of photos of everything. When you said "check voltage on pin 5 of the yellow connector (blue wire)", i was not sure what you meant by "blue wire" when I looked at the image you provided. It was only when I was re-attaching the connectors and putting everything back into place that I understood what you meant but it was too late at that time to check the voltage because I had to leave very soon after.

I will be busy for the next few days and the car will be on the road all weekend so it will be next Monday before I get a chance to have a look at it again but at least it gives me plenty of time to study the pictures and process everything I saw yesterday.

[adurer]

Looking forward to see all photos. I believe many members would be more than happy to see them in high resolution, so I'd recommend creating an album on an image hosting website (I use PhotoBucket) and put a link in here. It is easier to explain how to repair something annotating a photo.

You identified right the blue wire, it is the the yellow plug wire corresponding to pin 5 (see below)

This partial wiring of the dashboard shows that battery voltage is present on pin 2 (red wire) and output of Vreg goes to pin 5. Because you have limited access space to PCB, I suggested to check voltages using yellow connector pins. If you feel confident enough, you can remove dashboard frame and plug back only the PCB (3 connectors - yellow, black, white). You have to measure as follows:

- with ignition key on, check you have battery voltage between pin 2 (red wire) and a known good ground (i.e. E5)

- check regulated voltage between pin 5 (blue wire) and known good ground

- with ignition key off, measure continuity (ohmmeter) between pin 10 (brown wire) and known good ground.

Come back and tell us what you found.

[dohnjoe]

Very good photos.

Edited 24 April, 2013 by dohnjoe

[adurer]

Till Simon gets back, if anyone else has dashboard cluster related questions, throw them in. I and other members will try to pinpoint the cause and find a solution. Only mention how the issue started and if you think it is related to any prior repair/fault.

Edited 24 April, 2013 by adurer

[adurer]

Any follow up?

[Musescu_A]

On 4/24/2013 at 08:31, adurer said:

Till Simon gets back, if anyone else has dashboard cluster related questions, throw them in. I and other members will try to pinpoint the cause and find a solution. Only mention how the issue started and if you think it is related to any prior repair/fault.

Same thing happens to me. Dashboard is dead but mine comes back alive when I rev the engine to about 3000 RPM. There's a discussion going on this thread here: