Hi,

My horn stopped working. Took it to my local garage who sent it to an auto electrician. He bypassed something (there seems to be 3 fuse boxes and umpteen relays). The horn worked but the dashboard lit up with ABS warning lights and almost everything else. Took the key out and the engine kept running. Needed to use the car so the garage undid the bypass.Horn no longer works I'm told that to correct everything, the cost will be £300-£700. I am basically clueless about electrics and don't want to get ripped off. 20 years ago, I'd have gone to Halfords and bought an airhorn, wire and a fuse. Why all this? Any suggestions based on similar experience would be welcome.

it depends whats wrong

if it the centrals electrics module then they arent cheap to buy/fit/code

you need someone with a vcds to check this fault as you can energise the horn etc using output tests to check cem

it could be

the airbag mechanism

the airbag loom

the wiring to the CECM

the CECM module

the horn relay

the wiring to the horn

Hi,

My horn stopped working. Took it to my local garage who sent it to an auto electrician. He bypassed something (there seems to be 3 fuse boxes and umpteen relays). The horn worked but the dashboard lit up with ABS warning lights and almost everything else. Took the key out and the engine kept running. Needed to use the car so the garage undid the bypass.Horn no longer works I'm told that to correct everything, the cost will be £300-£700. I am basically clueless about electrics and don't want to get ripped off. 20 years ago, I'd have gone to Halfords and bought an airhorn, wire and a fuse. Why all this? Any suggestions based on similar experience would be welcome.

For a start never use that auto electrician. Was he riding a horse, with a pair of spurs, leathers, and a pair of Smith and Westerns? But seriously, what he did is bad, the various modules that are our interfaces to horn/electric windows/etc are there for a reason, if an individual item fails it can be traced back and identified, through diagnostic tests triggered through that module. If something gets bypassed then that will generally lead to a failure of a greater 'master' system. A leads to B which connects to C which is connected to X, Y and Z. Diagnostics is what you need not an auto electrician, gone are the days of relatively simple wiring in cars. First off is interrogation of the car via computer to see what it thinks is wrong, then if nothing is identified then 'guided fault finding' can be followed (if at a dealership). If you don't want to get ripped off the dealer is always a safe but expensive bet, but some dealerships are better than others, there is a section on here with ratings and what not.