Not getting the horn

Lovely drive to see a chum this morning as the carpet is indoors still drying out and the snorkel seems to be now fully sealed.

However, the horn is no longer horning.
With the steering wheel buttons pressed, I can hear a click from the centre console.

With just a few weeks of TF ownership undermy belt, I am assuming that is one of the relays on the alarm PCB.
Therefore there 12V from the button to the PCB.

Do I assume that a wire comes out of the alarm module and goes to the horns?
Is that it?

And if that is the case, then a simple 12V test at the horn plugs will determine if it is wiring that is the cause?

Is there anything else that I should be looking at?

It's just too cold to be holding on to bits of freezing metal.

Yes the grounding, and both the fit and cleanliness of the terminals

Multimeter or a bulb accross the horn terminals. Get someone to press the horn button. If the circuit is live order a new/ 2nd hand horn. If the circuit is dead its the relay or fuse

Thanks very much for the advice.
It has been just toooooo cold and now too rainy to do anything.

Will check both and report back here.
The plug terminals are tiny.

Just one more thing. If it is the relay, does that mean sending the unit to Technozen for replacement soldered relays?

Although not as easy to find as other car relays they are available on the internet & if you are confident with a soldering iron & desoldering tackle it shouldn’t be too arduous a job. I am very familiar with the hot end of a soldering iron & wouldn’t think twice about getting stuck in, others who are less cavalier might think twice.
Another way to verify the horns (is your horn singular or plural?) is to run a positive from the battery & pick up an earth locally. Only the slightest touch on the contacts will make you jump, that could be a loud parp or a shower of sparks if you don’t get it quite right
M

Technozen is the best solution to the BCU relays , 'IF' you find it is faulty . With my BCU I decided to have all the relays replaced with the more reliable type as the car was a keeper and I didn't want the hassle of taking the darn thing out again. Just be aware of the fact that the unit is held in place by TORX + type screws , the bits are not commonly available but Technozen can supply these if you contact him before struggling to get the screws out .

John

AP, thank you again. I have soldered but not in the professional category. Would have to take the board out to see how close the adjacent terminals are. Middle son is more experienced than I - might be worth a 4-pack of Doom Bar or whatever he is drinking at the moment.

WorksC, thanks too. I do have a goodly selection of Torx bits but no Torx+ bits.

I can hear the relay clicking in the centre console so I am suspecting something further along the circuit, nearer the horns (I have 2 oddly because my reasearch shows that Project Drive removed one on my Apr 05 model).

Thanks again for your advice. If only I could bring myself to start touching 4degC metal.

I haven’t heard the term Torx+ before, can I assume it’s a standard torx screw with the security pip in the centre or do we have more / less lobes.
It never occurred to me that that style must be referred to differently, I have pipped & non pipped, I distinguish one to another by marking the pipped offering with red sharpie.
Other close relative tools get the sharpie treatment. It also helps me recover tools which are holidaying in my sons tool boxes & remind them that it’s nice to go away but it’s nice to come home again.
M

Good idea, AP. Sharpie.
The Torx+ is a 5 point bit rather than the standard 6 point bit.
It's on my Xmas list.

Thank you for that it’s really useful. I have both “inside & outside” torx from too small to apply any grunt, through to too big to be relevant for what I get up to these days & as I haven’t been faced with torx+ as yet, I’ll commit their existence to memory & panic if I’m called to strip an item down if so equipped.
M

Another thought that has just drifted across my neurones is; if the torx bit had six lobes & the plus has five, surely shouldn’t it be a torx minus?