Fitting an Stebel Nautilus Air horn to a GP...

obviously this involves working on your cars electrics so if unsure consult an auto electrician and this might void your cars warranty but.............


Right step 1...

remove your upper front grill this is a push fit so it needs a pull to remove there are around 10 clips on the top and 10 on the bottom start at the top at one end and with your fingers through the grill pull a bit at a time along the top from one end to the other and then pull the bottom row of clips..




once the grill is off remove the original horn with a 10mm spanner and unplug the wiring multi plug

now unbolt the top of the flat bar bracket.. you will notice that the upper hole is larger than the lower hole where you have just removed the horn from..

rotate it 180 degrees and bolt the bracket back in place so the larger of the 2 holes is ready to take the new Stebel Nautilus Horn... (don't know why the holes are different sizes i took mine out with the idea of drilling it only to find the larger hole)

now put 2 long lengths of heavy (no less than 2.5mm^2) cable (i used 3mm^2 and crimp a insulated female spade to each wire noting which is live and which is negative..

I wrapped the 2x 3mm^2 with an extra core of 1.5mm^2 which i left long at the horn end (you'll see why in a minute) with black insulation tape to make a loom.....

This horn MUST be connected to a relay and not just to the horn circuit if not you could melt the horn circuit wiring...

now bolt the horn to the bracket (its a tight fit with the front crash rail) with the black spacer provided and a drop of threadlock on the nut or use a nylock.




once bolted in place you need to connect up the rest of the wiring..

I opted to take the earth supply from the battery as its so close so i used a blue eyelet crimp onto the negative terminal.

for the live i did the same but put a 20A blade fuse holder in line (don't fit the fuse till you have finished)

now for that 3rd core you wrapped in the black tape..

you need to make a connection to the original horn connection on the live side you can either chop off the original plug ((bad idea for the warranty as there will be no way to refit the original horn))

i used a 110 red male spade crimp although these are like rocking horse droppings to source or you can use a scotch hook onto the white wire (black is earth) and bound in tape to hold it in place.



( a "bit" out of focus )

once this is connected DON'T PRESS THE HORN....

now you should have a few long lengths of wire floating about.....

i opted to put the relay in a water proof box to protect it but its up to you



and just tied it to the front crash bar with a cable tie...

now your ready to wire it up....

you should have 4 stray wires still needing a home....

you need to link the 2 negative wires (one from the battery and one to the horn) together using a big yellow through crimp but add a 30 cm lenght of 1.5mm cable to this (to power the relay coil.. and fit a blue female spade to this (after passing it through the compression gland if you use a water tight box)

put a blue female crimp on the live supply, live feed and horn supply

next wire the relay...

Pin 30 supply from the battery

Pin 85 negative supply from yellow crimp

Pin 86 wire from original Horn

Pin 87 Live supply to horn

Before putting the fuse in press the horn you should hear the relay click this shows its connected correctly...

now put the 20Amp fuse in and upset the neighbours