Thread: Replacing high tone horn

Are they not already on a relay circuit ?

Horn




Item Part Number Description 1 -Steering wheel horn switches2 -Central Junction Box (CJ3 -Fuse 124 -Horn - Low tone5 -Horn - High tone

GENERAL

Two horns are fitted to the vehicle; a high tone and a low tone. The horns are mounted on brackets, which are attached to the front end carrier assembly, on each side of the radiator.

The horns are operated by pressing one of the two horn switches, located on each side of the driver airbag, on the steering wheel.

The horns are also used by the vehicle alarm system. When the alarm system requires the horns to operate, the Central Junction Box (CJ provides a ground to the horn relay solenoid, closing the relay contact which in turn supplies battery voltage to operate the horns. For additional information, refer to Anti-Theft - Active (419-01A Anti-Theft - Active)


The horn circuit is permanently connected to battery voltage and therefore the horns can be operated at any time, irrespective of ignition switch position.

The horns are controlled by a relay which is an integral part of the CJB. The relay contact and solenoid is connected to the vehicle battery via a fusible link (Link 17) in the battery junction box and a fuse (F12) in the CJB. The horn switches, when pressed, complete a ground to the relay which energises the solenoid. The energised solenoid closes the relay contact and battery voltage is supplied to each of the horns. When the horn switch is released, the ground for the solenoid is broken, the solenoid is de-energised and the relay contact opens, cutting the voltage supply to the horns.

Good information Neil P, I will file that, do you have similar information for the automatic headlight sensor?

Originally Posted by RichardK

....do you have similar information for the automatic headlight sensor?

Autolamps

Overview

Thanks Neil P, I have all the pieces, after I absorb your post and assuming I can make sense of it (electrics are not my speciality ) I'll have a go.

I just put two new LR horns into my D2 yesterday. Those front plastics are delicate and there are a couple of screws that are somewhat hidden - you'll need a long Philips screwdriver to get the two that hold the under-wheeelarch guard to the body.

I haven't got a photo sorry. IIRC there was one on Urban Panzers' site. Maybe search for 'headlight trim' or similar and you'll pick it up.

I can't paste a link from my phone but later on I'll post the link to the ebay auction where I bought mine. Both high and low tone were less than $45 delivered ex-UK.

Having said that though it was tempting to put a Stebel Nautilus under the bonnet in a far more sensible location than the original placement. I have one on my bike and they are an impressively loud little unit.

Are you sure it's just the horn itself that's blown (ha ha, I'm so funny on a Sunday morning...')? You can work backwards from the horns themselves by placing your multimeter probes into the sockets you've pulled from the horns and press the horn buttons to see if there is any voltage reading on your multimeter. I was lucky and this was the case with mine. While doing my homework on this one I read horror stories about having to open up steering wheels and rotary couplers - I hope yours is as straightforward as mine was!

Originally Posted by RichardK

Thanks Neil P, I have all the pieces, after I absorb your post and assuming I can make sense of it (electrics are not my speciality ) I'll have a go.

yep, pretty sure the horn is faulty. The low tone horn still sounds so I'm assuming the fault is at the horn and not further back in the wiring and most of it should be common to both horns.