Technical Short circuit traced to the F1 engine compartment 70 amp fuse - Dashboard Unit Supply

[VictorB]

A short circuit has been traced to the the F1 70 amp fuse - Dashboard Unit Supply - situated in the engine compartment.

The insulation has come away from a bunch of wiring (1 inch in diameter) before it enters a control box situated under the centre of the scuttle. Could this be the problem. Of course this might have nothing to do with the short. Any advice gratefully received.

 

[The Panda Nut]

Well the wrapping wont be the actual cause but suggests the harness has been exposed to wetness from somewhere and it will be allowing water to get in places its not meant to be. It may be a faulty wire or corroded terminal (this doesnt need to be that obvious either) but the first thing to do is check where its earthed. Electricity will make its way down the easiest route if its not the earth point its supposed to use it will go soemwhere elose and cause all soerts of weirdness.

If you can locate any earth oints undo these, check the wires and endings are clean and bright. Clean the esrth bolt / hole and the bolt and nuts that make the earth connection. Also check the main battery to engine to chassis earth as thes are a known weak point and will magnify any other poor earth connections.

 

[VictorB]

Well the wrapping wont be the actual cause but suggests the harness has been exposed to wetness from somewhere and it will be allowing water to get in places its not meant to be. It may be a faulty wire or corroded terminal (this doesnt need to be that obvious either) but the first thing to do is check where its earthed. Electricity will make its way down the easiest route if its not the earth point its supposed to use it will go soemwhere elose and cause all soerts of weirdness.

If you can locate any earth oints undo these, check the wires and endings are clean and bright. Clean the esrth bolt / hole and the bolt and nuts that make the earth connection. Also check the main battery to engine to chassis earth as thes are a known weak point and will magnify any other poor earth connections.

Thank you for the prompt advice, much appreciated.

 

[The Panda Nut]

Thank you for the prompt advice, much appreciated.

You are most welcome, Im sure more ideas will be provided soon and if this doesnt prove to work.

 

[koalar]

Start at the beginning

Has fuse F01 blown

What have we measured to come to the conconclusion there is a short

Is the short going into F01 or coming out of F01

Is the short to ground or to power

 

[VictorB]

Start at the beginning

Has fuse F01 blown

What have we measured to come to the conconclusion there is a short

Is the short going into F01 or coming out of F01

Is the short to ground or to power

A testing device was used as follows:
Battery's positive terminal connector was removed.
With the ignition and all other electrical devices switched off, the tester was connected between the positive terminal of the battery and the positive terminal connector.
It lit up indicating a power draw from the battery even though no power should have been used.
Each fuse was removed in turn and the tester stayed lit except when the F1 fuse was removed, when it went out.
I believe this indicates that the short is located somewhere in the circuit protected by the F1 fuse.
I'm afraid I don't know enough to answer your last two questions:

Is the short going into F01 or coming out of F01?
Is the short to ground or to power?

Thank you for your interest.

 

[VictorB]

The F01 fuse has not blown.

 

[koalar]

I am not sure what we are testing here

The body computer is always powered on

Central locking, remote locking, clock all need to work without opening the bonnet and reconnecting a disconnected battery

Removing F01 is Basicly the same as undoing the battery

 

[VictorB]

Take your point, koalar, and appreciate your response.

The battery, a new one, goes flat after two days of non use, so there is a drain somewhere.

Agree that the items mentioned, central locking, remote locking, clock do need to work when the ignition is switched off, but should only draw on the battery when used. Some of the display may be drawing continually, need to check tomorrow.

Booked an auto electrician to look at it on Friday.

 

[koalar]

Nope

The body computer is on permanently, It goes into a low power mode and waits for a key response,

The clock is on pemently otherwise you'd have to set it every day

We can probably get to the bottom of this,

Do you have blue & me on your car

Do you have any way to measure amps

 

[VictorB]

Morning Koalar,

I don't have Blue and Me, at least if it is there I've never seen it or used it.

I do have an analogue multimeter. Never really understood how to use it, though.

It has 3 settings for DC mA 0.5 50 and 500.

I'm afraid I will need explicit instructions to use it.

Encouraged by your optimism.

Victor

 

[koalar]

That's great

We are going to fairly careful

As soon as everything wakes up the current is more than the meter can handle, especially if you accidently open the door and the interia light comes on as well

Let's start with a little history

Has the radio ever come on, on its own

Which car is it 2008 1.1 active for example

The battery discharges after 2 days, I take it after 2 days the car does not turn over or very slowly

Has the battery recently been changed


Any other symptoms, dash light warning lights for example,

 

[VictorB]

That's great

We are going to fairly careful

As soon as everything wakes up the current is more than the meter can handle, especially if you accidently open the door and the interia light comes on as well

Let's start with a little history

Has the radio ever come on, on its own

Which car is it 2008 1.1 active for example

The battery discharges after 2 days, I take it after 2 days the car does not turn over or very slowly

Has the battery recently been changed


Any other symptoms, dash light warning lights for example,

Carefully always good for me.

Has the radio ever come on, on its own
This has never happened.

Which car is it 2008 1.1 active for example
Dynamic 1.2 Dualogic

The battery discharges after 2 days, I take it after 2 days the car does not turn over or very slowly
Battery completely flat, no lights on the dashboard display at all. No response from starter at all not even the whirring sound which sometimes occurs if there is not enough power to turn the starter motor.

Has the battery recently been changed
New battery fitted about 2 weeks ago.

Any other symptoms, dash light warning lights for example,
Nothing normally. When the F1 fuse was removed the engine would turn over on the starter but wouldn't start and there was a warning about the power steering on the dashboard display. Withe the F1 fuse in place the engine starts and no warning lights present.

 

[koalar]

Right

Yes it's a pink suzuki I have here at the moment but it was cheap

Open the bonnet

Make sure the interia light is off

Then lock to doors either with the remote or keys

Disconnect the battery, and clean the top of the battery positive post

Put the dial on the highest amp setting
On this meter its 200mA (m is higher than u)

Move the red probe out of the common and into the amp setting

And fingers crossed take a reading by connecting one probe to the positive terminal and the other to the positive of the batterry

It will start quite high and drop within 30 seconds as the body computer switch back to low power mode


What are the two figures
Start and after it drops

 

[VictorB]

Just followed instructions. Not sure if my multimeter is up to it.

Picture attached - apologies for the size of the image - not sure how to make it smaller.

Tried the 200 setting and the needle swung instantaneously completely to the right and stayed there - didn't go lower.

Identical result at the 50 and 0.5 settings.

Victor

 

[koalar]

Great it should be less than 100ma after 180 seconds

 

[VictorB]

Great it should be less than 100ma after 180 seconds

Unfortunately the photo was just to show the multimeter control, not the reading.

The needle swung instantly to the right which I assume that with the setting at 500 indicates more than 500 amps.

If this is corrrect it would account for the massive drain on the battery.

 

[koalar]

Fiat panda

Unfortunately the photo was just to show the multimeter control, not the reading.

The needle swung instantly to the right which I assume that with the setting at 500 indicates more than 500 amps.

If this is corrrect it would account for the massive drain on the battery.

Yes over 1/2 an amp 500mA

They are close to 500 for the first 3 minuites and then drop down to less than 100

 

[koalar]

Fuse 01 feeds the fuse box to the right of the steering wheel inside the car

Let's confirm the amps with it removed then we can move onto the inside of the car

 

[VictorB]

With F01 removed, and meter set to 500amps, the needle swept to the right as before but after 10-20 seconds returned to the centre of the readings say 150. It was never steady though with a lot of wavering and some swings to the maximum again but always returnin to around the 150 reading.