Horn weirdness??

[bubba dubba]

Hi, hope somebody can point me in the right direction as im confused???... (it doesn't take much to confuse me )
right I changed my standard horn for one of them awooga type things (yes I know im a child) and all was fine for a couple of years.
M.o.t time of year and when it goes for the test the horn wont work so the garage just chucked on a cheapy to get it through, now they have not changed any wiring only unplugged the awooga and plugged the new one in. I tried the awooga and nothing apart from the dash lights dimming and the fuel gauge needle shoots up to full ??.......so must be faulty I thought and bought a new one, now ive tried that one today and guess what same thing????....plug in the cheapy and it works but the gauge needle still shoots up?
now obviously something has changed where do I start as its things like this that drive me crackers!.
oh by the way its a separate button that's earthed and fused to the fuse box and then two wires to the horn.
Im sure its probably something simple but I am hard of thinking :?

any help would be great, thanks in advance.......................kev

 

[gas1man]

Always check the earth's first

J & P

 

[samgopsill]

On the subject of earths, do the wires go through to the underside through a grommet etc? I've had it before there the insulation gat stipped against the body (from pulling the wires about to swap horns) and the 12v gos straight to earth (body) when you hit the button, potentially causing the voltage to 'back feed' into your fuel guage, and also pulling more current (dimming everything else) how massive is the fuse for your horn?

Hope this helps

Sam

 

[bubba dubba]

Hi, thanks for taking the time to help, you are both sort of confirming what I was thinking, im going to check earths, I might even renew the wires as I didn't even think about the body chaffing possibility.
and as for fuse size ive no idea, but thats a good point, im starting to doubt its got one now (sure i saw it a while back) or if it has its probably been bodged if it hasn't blown?

thanks again..............kev

 

[Bluesnailman]

just doing some research on my fluctuating fuel gauge and came across this - now, my horn is being weird also...

coincidence?

did you find the solution to the problem - if so can you share?

 

[bubba dubba]

Hi,
I managed to sort this out today, it turns out the previous owner had taken an earth from the back of the fuel gauge and run it to the push button for the horn? (I have no idea either).
Anyway I changed this and run a new earth to the van body instead, "great I thought ive cracked it" but no not yet.
so the fault must have been in the live feed to the horn, (as it used to work before with the earth wired that way) I think it must have rubbed through on the body somewhere and been shorting out, weird that it would power a small standard horn but not the awooga jobby?
so I ended up renewing the live from a spare spade on the fuse box and put a in line fuse in for good measure.

hope this helps with your electrics...............kev

 

[Bluesnailman]

Hi,
the previous owner had taken an earth from the back of the fuel gauge and run it to the push button for the horn? (I have no idea either)

Ok Horn Weirdness was a good subject title......

I'll have to put mine down to the steering column collar and a dodgy fuel sender...