Question three - horn - electricery

[JPSmit]

So, My horn has been flatulant lately - I do have it on a relay but, that seems irrelevant to my question. Now, when I press the horn, nothing happens except I hear the relay click. If I disconnect one horn the other works perfectly. If I reverse it the other horn works perfectly. They are hooked up with the same power wire - in parallel not in series and likewise they have the same ground wire.

My brother in law the electrician looked at it at Easter and said I needed a new battery - I put in the new battery tonight and nothing changed.

What am I missing, any thoughts? (and yes I can just use one horn but I don't want to)

thanks!

 

[AngliaGT]

What is the speed of a swallow?

 

[smaceng]

Horn problems are usually due to poor grounds. Your car may have some devil in it as the symptoms don't make it obvious was is causing it.

 

[Gliderman8]

What happens when you temporarily bypass the relay and apply power? Just wondering if the contacts in the relay are pitted.

 

[JPSmit]

What happens when you temporarily bypass the relay and apply power? Just wondering if the contacts in the relay are pitted.

same thing - and I have swapped out the relay - though admittedly not the harness

 

[Bayless]

Sure sounds like too much resistance somewhere in the circuit. Most likely the ground but could be in the harness. if not the ground, try a jumper straight from the battery to the relay. If that doesn't work then another jumper from the relay to the horns. One of these should at least tell you where the gremlin lies.

 

[SD Bugeye]

You say you have it on a relay could be the points can't pass enough ampere to satisfy both bigger or separate relays?

 

[Gerard]

What is the speed of a swallow?

If you are going to quote Python, get it right man...

Bridge keeper: What... is the air-speed velocity of an unladen swallow?
King Arthur: What do you mean? An African or European swallow?

 

[Gerard]

If you have the horns with 2 spade terminals, make sure you using the contact that goes to ground. The purple with black tracer are the ground circuit wires.

 

[JPSmit]

I am still perplexed by this. I tore out the whole relay and my manufactured grounds last night - reinstalled it according to the factory and, no change. So, for now one horn and see what happens.

 

[AndriesS]

if you have a test light or multimeter I would suggest connecting them to the horn wires, As per your case disconnect the one horn and check on disconnected horn wires, light should go on show 12V when horn is pressed which indicates wires are intact, now connect horn and see if you still get 12V or the light goes one, if not it means that you have serious resistance on the horn circuit. Then look at the wiring providing power to the high amp side of the relay.


Since monty etc has been quoted I can throw this one in, your 2 horns are out of phase and thus are cancelling each other out and that's why you don't hear a thing.

I assume you have pt 85 and 86 linked to your horn button and 12V and then 30 to 12V via a fuse and 87 to the positive on the horns

I'll also check if one of the horn connectors does not bleed to earth, i.e. measure the resistance between the spade connector and the mounting bolt, they should all have infinite, if not and one has 0 impedance then that is the spade that should be connected to earth.

 

[JPSmit]

Thanks! this is helpful - will take a look. The relay is now gone but, will see what I can see. I am just heading out of town but, hope to drive to my first show Sunday. BTW, where in SA are you? One of my dearest friends is from Stellenbosch and another friend from Pretoria and yet another Cape Town.

 

[AndriesS]

Hi John ,

Apologies was on leave for a bit and missed your post, rather late than never. I'm in Pretoria.