FUSE warning light and Battery warning on.

Birchall

Birchall

Dick Chown Award 2016
My son just rang, his wife's A2 has just flashed up the Battery light symbol in the centre dash screen and a "FUSE" warning near the speedometer.

My guess would be that one of the main fuses has blown, either the one on the positive terminal of the battery or the one under the front passenger floor. I have told him to check these.

I have never seen this warning symbol "FUSE" ever before, has anyone else seen it?

Any help would be appreciated.

Cheers
Steve B
 
fuse.jpg


This is it, a new one on me.

Steve B
 
Catnip64 said:
Steve,

Looks like it could be the fuses for the dash itself: http://www.audi-sport.net/xf/threads/dash-displays-fuse-in-place-of-trip-reading.48226/

Hope this helps.

Steve
Click to expand...

Hi Steve,

Thanks, it does help, because he rang a couple of minutes ago and said that it is fuse 1 that has blown and when he replaced the fuse that blew straight away again.

So there is a short somewhere but I have a feeling that it will not be easy to pinpoint, but I will get him to check out the instrument cluster, but as you can see in the picture it seems to have power and the other lights and date etc are all on.

It is a standard car nothing "aftermarket" so not going to be something botched on an install of sat nav, or anything like that.

I will let you know how we get on.

Steve B
 
This same thing happened to Tagscuderia's FSI. It took me aaaaaaages to find the cause, but it turned out to be a short in the cigarette lighter socket. The interior illumination circuit fries something in the instrument cluster which in turn causes Fuse 1 to blow over and over again.

Can your son dismantle the handbrake and disconnect the cigarette lighter from beneath?
If the fault is the same as I've seen before, the repair will require a new instrument cluster, but disconnecting the cigarette lighter removes a genuine risk of fire.

Cheers,

Tom
 
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Thanks Tom

thay is certainly a possibility in this case. I think that someone has worked on the cigarette lighter socket in the not too distant past.

My Son will check this when he gets home tonight.

Cheers
Steve B
 
Hi,

possible internal damage to the instrument cluster should be taken as a warning to anyone considering modifying the interior illumination circuit to use it to supply additional loads or altering the lighting systems.

The instrument cluster contains a variable output driver to power the various panel illumination bulbs for the switches and sockets. It is the instrument cluster which controls the brightness of those illumination bulbs and overloading or shorting the output would understandingly cause damage to the driver in the cluster. There doesn't appear to be an external fuse between the cluster's power output and the load so if anything blows, it will be inside the cluster!

Tom, do you know if there is a PCB mounted fuse inside the cluster protecting the output or whether overloading the lighting output actually causes a component (e.g. power transistor / voltage regulator) in the power control circuit to fail?

Andrew
 
If there isn't a fuse for that then surely it would be a pretty pointless message.

Not it a lot of use putting a big FUSE warning if it wasn't fused?

so I would hope it is fused. Or that the fuse it is highlighting is the number one fuse?

Steve B
 
ajsellors said:
Hi,

possible internal damage to the instrument cluster should be taken as a warning to anyone considering modifying the interior illumination circuit to use it to supply additional loads or altering the lighting systems.

The instrument cluster contains a variable output driver to power the various panel illumination bulbs for the switches and sockets. It is the instrument cluster which controls the brightness of those illumination bulbs and overloading or shorting the output would understandingly cause damage to the driver in the cluster. There doesn't appear to be an external fuse between the cluster's power output and the load so if anything blows, it will be inside the cluster!

Tom, do you know if there is a PCB mounted fuse inside the cluster protecting the output or whether overloading the lighting output actually causes a component (e.g. power transistor / voltage regulator) in the power control circuit to fail?

Andrew
Click to expand...

Andrew is absolutely correct; it is the instrument cluster that drives the interior illumination circuit.

Andrew, as far as I know, there is no PCB-mounted fuse protecting this output (I've certainly never noticed one, though I'm now inclined to check). When Tagscuderia's car suffered from this problem, a section of the cluster's motherboard was fried. I never had chance to investigate what exactly had failed, as Tagscuderia took the cluster back to Audi in an effort to get some goodwill. I know he was unsuccessful but don't know what happened to the cooked cluster. He may still have it.

Birchall said:
Not it a lot of use putting a big FUSE warning if it wasn't fused?

so I would hope it is fused. Or that the fuse it is highlighting is the number one fuse?
Click to expand...

The FUSE warning on the display of the cluster does indeed relate to Fuse 1 of the main fuse board. You may ask how the cluster can still be powered if the fuse has blown, but the cluster receives power via two sources, so is able to report a blown fuse.

Cheers,

Tom
 
My heart sank when I saw the thread title! Description fits mine perfectly :(
Originally Audi ran diagnostics and declared that the cluster was faulty so I picked up a brand-new cluster which installed fine but then 6 months later that one blew. I'm now on my 3rd set of clocks - expensive!!!

I had noticed an occasional buzzing from the cigarette lighter but it worked fine so unfortunately it was one of those things that got put off. As it happens the lighter design is not very robust and relies upon being aligned between 2 plastic clips; mine wasn't and could rotate on its axis, eventually sending 12V to the clocks via the interior illumination circuit. Anyone removing the lighter should double check that it's seated correctly before reinstalling!

I sent my fried clocks to Sarge to have a play with in his spare time - it was worthless to me (this was before myself and Tom figured out where the fault originated). At the time he didn't have the equipment at hand to troubleshoot (he'd loaned it to a friend) and it has since been cannibalised so the only fix that I know of is a new cluster.
 
Another TEN out of TEN for Timmus and a big THANKS to the other contributors.

Tracing an electrical fault that is causing a fuse to blow can be s nightmare. So to be given a steer on where to look, and to get it right first time is amazing.

My son had fitted a replacement lighter socket a while back and it was a two wire one from another make of car.
He hadn't spotted that there was a third wire (for the illumination) and so it was left unconnected.

Over time the illumination wire had moved back to its original position and eventually touched against the main live wire.
Luckily enough it seems that no permanent damage was done and after replacing Fuse 1 everything is fine again.

I sm so glad that, yet again, this forum and the great people on it have come through yet again and saved a LOT of effort and pain.

Thanks Tom, but also thanks to Andrew and Tagscuderia for their accurate and useful input too

Steve B
 
Birchall said:
Another TEN out of TEN for Timmus and a big THANKS to the other contributors.

Tracing an electrical fault that is causing a fuse to blow can be s nightmare. So to be given a steer on where to look, and to get it right first time is amazing.

My son had fitted a replacement lighter socket a while back and it was a two wire one from another make of car.
He hadn't spotted that there was a third wire (for the illumination) and so it was left unconnected.

Over time the illumination wire had moved back to its original position and eventually touched against the main live wire.
Luckily enough it seems that no permanent damage was done and after replacing Fuse 1 everything is fine again.

I sm so glad that, yet again, this forum and the great people on it have come through yet again and saved a LOT of effort and pain.

Thanks Tom, but also thanks to Andrew and Tagscuderia for their accurate and useful input too

Steve B
Click to expand...

This is absolutely excellent news. I'm really pleased this is sorted without issue.

Does the interior illumination circuit still work properly? I expect it'll work fine on units like the stereo and climate control panel because these items illuminate via a CAN message, but the cluster is directly responsible for illuminating the items in the headlining, the ASR switch, the headlight switch, etc. Do all these items illuminate and dim properly?

Cheers,

Tom
 
N.B, it was only the ring light around the lighter that stopped working on mine, all other interior lighting was a-ok. But if Fuse 1 is no longer blowing then he had a lucky break - mine kept blowing (instantly, didn't even need to seat the fuse).
Great news Steve, my car likes to have unique problems so glad to see that his isn't likewise afflicted!
 
Hmm. I am finding the the lights on the cigarette lighter and asr switch are dimly illuminated when I plug in a USB socket - I wonder if it has a loose connection inside feeding power back into the lighting circuit. Better check the socket...


Sent from my iPhone using Tapatalk
 
Pinkythelabrat said:
Hmm. I am finding the the lights on the cigarette lighter and asr switch are dimly illuminated when I plug in a USB socket - I wonder if it has a loose connection inside feeding power back into the lighting circuit. Better check the socket...


Sent from my iPhone using Tapatalk
Click to expand...

Or maybe you're powering your USB charger from illumination feed?
 
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Birchall said:
Another TEN out of TEN for Timmus and a big THANKS to the other contributors.

Tracing an electrical fault that is causing a fuse to blow can be s nightmare. So to be given a steer on where to look, and to get it right first time is amazing.

My son had fitted a replacement lighter socket a while back and it was a two wire one from another make of car.
He hadn't spotted that there was a third wire (for the illumination) and so it was left unconnected.

Over time the illumination wire had moved back to its original position and eventually touched against the main live wire.
Luckily enough it seems that no permanent damage was done and after replacing Fuse 1 everything is fine again.

I sm so glad that, yet again, this forum and the great people on it have come through yet again and saved a LOT of effort and pain.

Thanks Tom, but also thanks to Andrew and Tagscuderia for their accurate and useful input too

Steve B
Click to expand...

This was my exact feeling when I joined back in 2009, as found solution to my brake switch problem that I was quoted 2-300 euros to fix here in Cyprus. And that feeling has grown stronger ever since. Great club!!
 
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