I’ve just bought a set of 24v horns for my truck which need at least 60psi air supply,anybody out there had these fitted?,or know where is best to get the air supply from(which tank?),also i need a switch to switch back to the normal horn wired up as well.
ANY POINTERS■■?
Ive got a twin trumpet set fited to my 7.5t Eurocargo pull chain, the lot. I’ll find out tomorrow how there fitted for you but believe me their bloody loud even if they are fitted to a 7.5 tonner 
i want it loud,as i was very nearly wiped out by a french lorry driver on the m6,and as i drew up to him,i hit the horn…and might as well had been on a moped 
For the air supply youll need a T-piece and a length of 6mm pipe which can be connected to the drivers seat (assuming its of the adjustable air type.) Just cut into the seat that feeds the pipe and re-connect with the T-piece. The volume will be decided by however many decibels the horn is designed for
Regards
Trev
Trevor Parry:
Just cut into the seat that feeds the pipe and re-connect with the T-piece.
Your boss may not be too happy if you do it this way around 
CM:
Trevor Parry:
Just cut into the seat that feeds the pipe and re-connect with the T-piece.Your boss may not be too happy if you do it this way around
Ill re-phrase that - just cut into the pipe that feeds the seat :laughing: :laughing: :laughing: Now you know why I dont post on here too often - too frightened of making a fool of myself Thanks for bringing it to my attention CM - I must be listening to too much music by the band who made the album in your avatar 
Regards
Trev
Trevor Parry:
CM:
Trevor Parry:
Just cut into the seat that feeds the pipe and re-connect with the T-piece.Your boss may not be too happy if you do it this way around
Ill re-phrase that - just cut into the pipe that feeds the seat :laughing: :laughing: :laughing: Now you know why I dont post on here too often - too frightened of making a fool of myself
Regards
Trev
A brother Floyd fan…all is forgiven.
Where in Ilkeston are you Trev?
I live on Grass St ( ) which is off Charlotte St CM (off Heanor Rd) and it has a handy little pub at the bottom called the Live & Let Live
Regards
Trev
Does that mean that everytime you sit down…you get the horn…
not enough air pressure from the seat supply!!, they will work but not fully, dont tap into any part of the brake system!! find the air tanks and take a supply from their not to hard to do, or if your horn is driven by air take a supply from that, I.E volvo / daf, guess a few others have air feed horns,
what you can do is tilt the cab and tap in to the susspention feed, you will have to drain the air tanks out! or when you cut into the line you will get a tanks full of air in your face!!!
this way you WILL get the 60psi for the horn and as for the switch go to maplins and get a dpdt switch (double pole double throw) and a bit of wiring will have to be done so you can select the horn you need ie electro horn for ‘please get out of my way!’ or air horns for’ GET THE [zb] OUT OF MY WAY!’
just find a blank switch cover on the center consol for the switch, or try to get one off merc as the actros can have the switch in it ( dependant on type) as it has pics of airhorn and elec horn on it!!
hope this helps and you get it running. 
Edited for language. If it needs little stars to get it past the Auto Censor that’s the clue it’s not allowed. Coffeeholic
Sorry mate but know one has a clue how they were fitted on our wagons but it took two blokes about an hour all in so I guess its quite a large job. I think they knew what they were doing.
it’s different for each truck.
pay a visit to your local dealer and ask a fitter there or wait until it is next in for service and ask then, if you have the truck serviced overnight then you may be able to get them to fit them for you for cash on the side.
if you are fitting train horns then it is best to split the horns from the moulded circuit board, this is the black plastic square in the centre of the bracket with 4 wires coming from it.
if you look at it you will see that it contains a wax like substance in the middle, this is the only protection for the electrical system inside and it breaks away over time, make sure you fit the black box inside the cab area and feed the wires to the horn.
invest in a proper switch for the dashboard and leave the other horn alone.
if you want full control of a pair of train horns leave the black box out completely and fit 2 switches for the horns, one for each tone.