Vauxall Astra N reg (95) HELP please car horn is draining battery

MAX71

Hi
I would be grateful for any advice as money is very tight at the moment. Recently bought this astra and she is in great nick having been looked after by two elderly gentlement from new. Full service history etc. No probs but the car horn was disconnected and when my husband re connected it the battery was dead the next day so we did this on and off for a week and each time the horn was plugged in the battery was dead. When we left it unplugged I have no problem with the battery at all!?
The battery is fairly new so could someone please tell me why the horn is draining itliek this and what can I do or will I have to do to put this right as obviously for legal reasons I do need the horn connected, I can't drive around with no horn and its bugging me what is causing it do do this?
Thank you for your help,
Max

molerat

A short circuit in the horn wiring somewhere. You need to trace the wiring with a multimeter to find it. If the horn is disconnected directly at the horn it seems fairly straightforward where the fault lies. Does the horn work when connected ?

societys_child

If by disconnected you mean the wire has simply been removed from the horn itself then buy and fit a new one - ebay / halfords etc - around £12

MAX71

Thanks for your replies - yes the horn works fine when it is connected. We now see that the previous owner simply disconnected the horn because it drains the battery. At least we know what the problem is, but I wanted to know why this is happening? and what is involved in fixing it and the cost?
Sorry to be a pain. Thank you for your help.
Max

Horseunderwater

Just buy a whole new horn and some new wiring to thread through. Fiddly but cheapish on the whole. Once all re wired and replaced, hopefully will work fine.

Strider590

Sounds like previous owner may have wired something else into the horn circuit.

OR the car has been in a front end accident and the repair left a short circuit somewhere.

mikey72

I'd just go for the faulty horn.

colino

More than likely, if the horn works OK when you connect it (and isn't continuous), the relay is U/S.

mikey72

Contacts dirty, conducting with a high enough resistance to not actually sound the horn, but enough current to flatten the battery when they should be open? Find the relay and pull it out.

MAX71

Thanks to all for your responses. As it seems it could be a number of things to look for I will have to take it to a garage and get them to check it. I will report back once I've sorted it as it may help someone else. Will have to wait a week or so as its having a new cambelt next week and can only afford that expense this month! Thanks again.

Lum

Are you reconnecting it in the engine bay, right by the horn?

If so then just replace the horn. It doesn't have to be a specific Vauxhall horn either. So long as it will physically fit in the space and can be bolted down securely it will work.

On my old Passat, where the horn had been replaced with a discus shaped blob of rust, I replaced it with a £15 set of Halfords air horns as they were the cheapest option.

These are a little bit more involved to wire up but they worked fine, passed several MOTs and once caused a taxi driver to crash into a central reservation fence after I beeped it in response to his drifting across the lane divider toward the side of my car.