300tdi 110 - horn not working

[steveG]

The horn on my '99 130 isn't working. Have tested the horn itself and it works fine, interior lights etc which are on the same fuse are working.

AFAIK there's no relay in the 300tdi horn circuit, so that just leaves wiring, plugs and horn switch itself :(

Any known issues with the horn circuit before I start tracing it through? I did a search for previous posts but didn't come up with anything.

Steve

[BigBlackDog]

When I got my 95 130 the horn didn't work - turned out the horn had been removed!

[windsock]

The horn on my '99 130 isn't working. Have tested the horn itself and it works fine, interior lights etc which are on the same fuse are working.

AFAIK there's no relay in the 300tdi horn circuit, so that just leaves wiring, plugs and horn switch itself :(

Any known issues with the horn circuit before I start tracing it through? I did a search for previous posts but didn't come up with anything.

Steve

I watch with interest. i have been trying to track a problem in a 1984 110. Replace the fuse, use the head light flashers as in pull the indicator lever back to flash oncoming traffic and the fuse will pop on the 3rd or 4th 'flash' and the horn will no longer work. Frustratingly, I replaced the whole indicator cluster in the hope the short was fixed but the problem persists. So, as stated above, I watch with interest.

[steveG]

I've traced the issue with mine back to a faulty horn switch in the indicator stalk.

Windsock - have you tried simulating the headlight flash at the connector plug for the stalk? Might help determine whether its actually in the wiring somewhere or still something weird going on in the stalk. Seems unlikely with a new stalk, but not impossible.
Maybe LR installed "don't flash too much" protection ;)

Steve

[rar110]

I had an ongoing fuse problem with the horn circuit. It ended up being the horn, which was only 2 years old, a quality brand, from a supplier to emergency services vehicles. It was quite expensive relative to even a Bosch unit, which has been problem free for the 1st six mths.

[landoman]

Strange thing ...to add sound proofing to the front floor area of my 110 I had to disconnect the
door internal light switches ( located in the lower front door jams ...when you open the door they pop out switching the internal roof light on ,when you close the door they press in switching the internal roof lights off )

I did this to aid in the pulling back of the moulded plastic floor covering around the firewall area .

When I reconnected them I found my horn was not working ........so, (as you do) I searched AULRO........and it talked about the interrelationship between the high beam flash function that is also on the same stick as the horn ......so I went and turned on my lights and flicked the high beam on and off a few times and low and behold my horn now works.

Can anyone venture what might have happened here ........I'm glad my horn is back working ....but would like to understand what happened ........

[ezyrama]

Only thing I can think of is, if they use all use a common earth return and somehow you had a bad earth after you removed the door switches. The high beam will draw a lot more current than the interior light and the horn. Stranger things have happened with Lucas electrics. Flicking the high beam on and off could have re-initiated a decent earth. My 300tdi disco earthed out the starter motor through ten handbrake cable and melted the cable to the nylon sheath. The only was I could stop it was run an earth strap from the battery to under the front injector bolt