The Triumph Dolomite Club - Discussion Forum

Hi All,

im finally blowing the cobwebs off the dolly. I'm sorting some of the easy bits myself before the serious stuff gets looked at professionally. The horn hasn't worked for a while on my 1850hl. I've got as far as finding out the stalk button has melted. I've got a replacement cap which will sort that once I take it down in size. Even now the horn won't work although I do get a faint noise like it's trying to sound.

So, I've our purchased some modern after market snail horns and I'm about to bolt them on (positive and negative terminals are a bit of a mystery as there's no markings) and I'm concerned they may be to high powered and may melt my stalk button or worse other wiring. I'm really looking for advice on if I need to relay them or not, if so what relay do I need and where's the best place to locate it.

I've done a bit of wiring before but only replacement or repair. Not modifications so I'm needing some advice!

Cheers

Or am I right I’m thinking if they are just 12v high and low horns like the originals they will be no higher risk than the setup that’s been on the car since new?

They should act in same way, and take no extra power.
If your old horn is metal? press the horn button and get someone to give it a crack with a hammer
They more often than not spring back into life

dollyman wrote: ↑Fri Sep 29, 2017 10:43 pm They should act in same way, and take no extra power.
If your old horn is metal? press the horn button and get someone to give it a crack with a hammer
They more often than not spring back into life

Yeah they are the original metal ones. I have already given them a pursuavive hit with a hammer, but I didn't depress the button while doing so. Will give that a go tomorrow before I mount the new ones in place!

Thanks for the reply!

On the original horns there is a small screw near the terminals. Tweak this one way or the other and you may get them to work. Get some penetrating oil on it first though.

Disconnect one horn and the try operating the remaining horn as some times this will get the horn to work as not such a large current load is being taken from the battery and the voltage will be a bit higher. Then swap over and attempt to get the out horn to work. Once freed up with any luck they may both work together.

I was also doing this recently on another variant. The way I like to fault find it is to connect a sealed beam light unit in place of one of the horns. If it lights at full brightness its the horns themselves.
If it lights dimly the next check is to see where the voltage drop is. If you can measure more than about 1/2 a volt from the earth side of the light to a good earth, the earthing needs cleaning up.
If you measure less than 11V from the live side of light its going to be the push-switch or more likely the fuse with the purple wire on it . But it can also be the wiring into the column switch.
Using a sealed beam unit means the current is roughly the same and it doesn't annoy the neighbours when looking for an intermittent fault.
I believe the current consumption is about 3.5 Amps.
Tony.

I second what Mart has said. I had a similar problem where I could have either horn working but not both together. I twiddled the adjuster screws and problem solved. I also remade the spade connectors, cleaned up the terminals and sprayed some white grease on the connections to prevent future corrosion.

Thanks for all the info. Seems the top horn is a dud, it did sound intermittently after messing with the screw as suggested and also disconnecting the lower horn. But reverted back to clicking regardless of screw adjustment quite quickly.

The lower horn sounded first time when connected on its own. Sounds loud enough just using the lower to me. So I'll stick with that to keep the original look rather than fitting the plastic modern ones.

If I connect the top one though the lower also fails to sound, so maybe I do have a slight voltage issue! Leaving one if the spade connectors off the top horn solves my problem for now

Oh, forgot to say the lower horn wiring also failed to get the top dud horn working. So guess it's had it's day.

I would suggest that you make a point of facing the horn down so that in the wet any rain does not get driven into the horn.