horn not working after swap

For all electrical questions; Alternators including fitment; Light connections/wiring; Instruments; Gauges; MFA; Heater blower (not coolant related) issues etc etc.
Forum rules
Hints, tips and guides for repair and modification - the FAQ section on the main website is worth checking first for information relating to common faults and technical help. Useful posts and guides will be added to the FAQ http://www.sciroccoregister.co.uk/scirocco-faq
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

horn not working after swap

Post by type53b »

OK I need some advice here please, car is an 82 mk2 gt, it has the old series1 fusebox. I decided to get rid of the old single horn that worked perfect but looked like it was dredged out of swamp and fit dual horns that are out of a 2004 Passat. I got a guy in work to solder the 4 wires onto my 2 wire connection block,positive to positive, negative to negative. All nicely done with heatschrink and all. I tested them off the car and they worked perfect. I then fitted them to the car and zilch. When I press the horn buttons I can hear the relay clicking at the fuse box but no horns, when I put power to them off the battery they work but when connected them back, again nothing jut the relay clicking. I checked the fuses and no 9 was missing???? So put a fuse in there and still nothing,relay still clicking. I change the relay,still no horns ,just relay clicking. One other thing, between taking the old horn out and fitting the new dual one's there was a lapse of about 5 months. The car is off the road getting slowly restored, anyway in that 5 month lapse I took off the old pierburg carb and fitted a brand new weber. Now reading up on the wiring diagram in the Haynes book of lies it seems fuse 9 covers the horn and the electrical Gubbins for the pierburg carb that is no longer there but the wiring for it still is. I should also point out I was never near the fuse box before today so fuse 9 must have being missing all along but yet I remember the old single horn worked! My brain is going into free fall with this so any advice is much appreciated. Another thing why is the relay even clicking if the no 9 fuse is missing? I though there would be no power to it if the fuse gone. Hopefully someone knows, thanks


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
steve bain
Posts: 630
Joined: Wed Apr 15, 2009 11:01 am

Re: horn not working after swap

Post by steve bain »

I don't think this is helpful but i had horn problems recently. On mine there are two fuses relating to the horn, one protects the horn wiring, the other the relay. On mine it was slots 18 and 20 i think. Others mentioned the earth on the steering rack and also the earth on the back right of the cam cover. at least the relay clicks so you know its not steering wheel issue so must be between fusebox and horn


Image

My build thread:
viewtopic.php?f=19&t=14083
PeteGLi
Posts: 918
Joined: Thu Mar 05, 2009 8:37 pm
fill in the right answer: 10
Location: Essex

Re: horn not working after swap

Post by PeteGLi »

Fuse 9 is for one of the headlights, I think. Try fuses 16 or 18.


mark1gls
Posts: 3954
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: horn not working after swap

Post by mark1gls »

If you fit the old horn back on does it work?
Horn fuse in slot 16 and 15amp fuse.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
steve bain
Posts: 630
Joined: Wed Apr 15, 2009 11:01 am

Re: horn not working after swap

Post by steve bain »

slot 16 for the horn. slot 18 for horn relay...

unless yours is the earlier one, in which case it is fuse 9 which a 1982 car would be according to this site.

http://www.cabby-info.com/electrical.htm

due you have blade or bullet fuses? if blade, slot 16 and 18, if bullet, slot 9.


Image

My build thread:
viewtopic.php?f=19&t=14083
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

steve bain wrote:slot 16 for the horn. slot 18 for horn relay...

unless yours is the earlier one, in which case it is fuse 9 which a 1982 car would be according to this site.

http://www.cabby-info.com/electrical.htm

due you have blade or bullet fuses? if blade, slot 16 and 18, if bullet, slot 9.
I have the early series 1 fusebox with the bullet fuses so it must be 9


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

mark1gls wrote:If you fit the old horn back on does it work?
Horn fuse in slot 16 and 15amp fuse.
Sadly I drop kicked the old horn into the nearest bin, fool that I am! I have the early series 1 fuse box so there are only 15 fuses in it.


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

steve bain wrote:I don't think this is helpful but i had horn problems recently. On mine there are two fuses relating to the horn, one protects the horn wiring, the other the relay. On mine it was slots 18 and 20 i think. Others mentioned the earth on the steering rack and also the earth on the back right of the cam cover. at least the relay clicks so you know its not steering wheel issue so must be between fusebox and horn
I checked the earth strap between the steering rack and the body and it appears to be sound, the earth on the back right of the cam cover is good and is wired to the new weber. I will double check the steering rack one again with a multimeter but it is a bugger to get to.


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

PeteGLi wrote:Fuse 9 is for one of the headlights, I think. Try fuses 16 or 18.
Early type fusebox fitted only 15 fuses in it.


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
PeteGLi
Posts: 918
Joined: Thu Mar 05, 2009 8:37 pm
fill in the right answer: 10
Location: Essex

Re: horn not working after swap

Post by PeteGLi »

Ok.
Have you tried a different relay? 12v 40amp with a number 53 on it.
You could also try disconnecting the earth wires from the horns and running a temporary earth wire directly from the horns to the negative terminal on the battery?


type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

I put a relay 53 in . no Change still bloody clicking!!! Can you explain more about running the temporary earth wire from the horns?


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
PeteGLi
Posts: 918
Joined: Thu Mar 05, 2009 8:37 pm
fill in the right answer: 10
Location: Essex

Re: horn not working after swap

Post by PeteGLi »

If the horns work when directly earthed to the battery, then you know that you have a fault with the car's earth wire from the horns. If the horns still do not work, then you will need to check that you are getting power to the positive terminal of the horns.

When you tested the horns directly from a battery, did it make any difference if you reversed the positive and negative connections?


type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

I took the cables off the horns and continuity tested them, they were both good, however I disconnected all the plugs off the back of the fusebox and continuity tested plug A back to the horn connection just below the battery and while I got a good signal on the ground wire , I got zilch on the positive wire, so maybe this could be the problem????


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
User avatar
james butler
Posts: 2965
Joined: Fri Apr 24, 2009 1:54 pm
fill in the right answer: 10
Location: birmingham

Re: horn not working after swap

Post by james butler »

connect a bulb between the positive and negative terminals of the horn wiring and see if it lights up when you press the horn. if it doesn't connect a new earth lead between the bulb and ground it to the body, if this works then you have a bad ground if it doesn't work you have a bad live feed.
out of curiosity on the early horn it doesnt earth through the horn to the body so only require a live feed?
the dual horns need a live and earth to work.


I dont mind project cars but I HATE SANDING!!!
type53b
Posts: 175
Joined: Tue Jul 07, 2009 11:12 pm
fill in the right answer: 10
Location: ireland

Re: horn not working after swap

Post by type53b »

james butler wrote:connect a bulb between the positive and negative terminals of the horn wiring and see if it lights up when you press the horn. if it doesn't connect a new earth lead between the bulb and ground it to the body, if this works then you have a bad ground if it doesn't work you have a bad live feed.
out of curiosity on the early horn it doesnt earth through the horn to the body so only require a live feed?
the dual horns need a live and earth to work.
I think you might be on to something here ! but.........I thought the original horn earthed thru the bolt that bolts it to the car body/chassis but yet the original wiring has 2 wires ,???
A brown wire and a black/yellow?? Maybe I need to put earthing straps from the two horns to the body ?cheers mate


remember, if it's got tit's or tyre's, sooner or later it's gonna give you trouble.
Post Reply