horn not working after swap

[PeteGLi]

What colour wires have you got coming out of the following plug terminals from the fusebox:
C5
A11
A7
E11
The horn has been wired in different ways over the years.
Only the horn button is earthed through the car body.
You will not get continuity on the positive wire (black/yellow) between the plug terminal and the horn terminal, if it runs through a relay, as that circuit is only open when the relay is energised.

[type53b]

Sorry Pete , the car is locked up in a shed in my job about 10 miles away, I am back in work Monday morning and I will check these wires and get back to you. What you said about no continuity between the block and the the horn connection is suddenly very clear to me. Would I get continuity between terminals 87 and 85 on the fusebox where the the relay plugs in and the horn connection? This electrics stuff is a black art!!!!! Thank you for your advice, its much appreciated.

[PeteGLi]

Would I get continuity between terminals 87 and 85 on the fusebox where the the relay plugs in and the horn connection?

No. You should get continuity between terminals 86 (input) and 85 (output) on the relay, which is the circuit to the horn push. When the horn button is pressed, this completes that circuit, energising the internal switch in the relay thereby completing the circuit between terminal 30 (power input) and terminal 87 (power output) for the horns.

By the way, some cars with single horns, did not always have a relay.

[type53b]

OK I will test these wire Monday morning. Fingers crossed!!!!!

[type53b]

Sorry Pete for not getting back to you sooner but work wise and family wise I've had a busy week! Anyway this has progressed from a pain in the ar$e to a total fukkin nightmare. I checked the pins you told me to check ..... C5 is brown,A11 is black/yellow ,A7 is brown and E11 is brown. Now I was faffin about at the fuse box and wiring and after an hour or two I started to lose the will to live, so I called the electronics guru in my job to come over and have a look. Any way I am at the driver seat pressing the horn buttons whenever he says to push them, while he is poking and prodding at the fusebox /wiring with a multimeter and then after a few minutes, I don't know what he poked or prodded but no 9 fuse blew and the relay stopped clicking. And now every time a new fuse goes in , the relay doesn't click anymore but some times the fuse is good and then no relay clicking and the fuse pops??? I noticed that every time the fuse blew the handbrake warning light would blink for a second.any way after a while we ran out of 8 amp torpedo/bullet fuses and the guru ran out of patience and legged it. Leaving me there without a clue!!!! I wonder could something be fried internally within the fusebox? Also the car starts and runs perfect . a bit more head scratching needed I think. Oh the joys!

[type53b]

I just thought I would let people know that I solved this problem by pure fluke. It was all due to me being a bit of a cabbage. I was soldering some wires in the boot harness last night. There is loads of bits off the car stored in the boot,one of them being the front washer bottle with its electric pump. Anyway, I picked up the washer bottle to moved it out of the way and I noticed it has the same T shaped connection that the horn harness has.after a moment I twigged where I had gone wrong. So after a quick search around the battery area I found the real horn T connection jumble up with the passenger side headlight wires. Muggins here plugged the washer bottle connection onto the horn harness!!! I felt like a complete gimp but happy it was sorted. Well I think it is sorted cos although everything is plugged in properly now, I haven't got any 8mp fuses left to put in slot 9 to test it. I have ordered some from the local factors so hopefully he will get them in tomorrow. Fingers crossed! Thanks to everyone who offered advice it was very much appreciated but in the end it was down to pure dumbness on my part.

[type53b]

Right back to square one on this nightmare! I got more 8 amp fuses and changed everyone for a new one. Horn still won't work and every time the horn button is pressed no 9 fuse blows.I thought maybe an 8 amp fuse wasn't strong enough seeing as there are dual horns fitted now. So I got a 10 amp fuse and just touched it up to to the no 9 fuse terminals but the moment I touched the terminals tiny little sparks came off both ends of the terminals, so I gave up on that idea sharpish. I think maybe there could be a chaffed wire or the fuse box might have an internal short/fault. Head wrecker!!!!!!!

[steve bain]

does sound like a wire is earthing somewhere which shouldn't be. sorry i can't be more help, but keep going, you'll get there

[type53b]

OK , I have finally sorted this out . long story short is the car was never fitted with a horn relay cos it only had 1 horn fitted as standard. So then muggins here fitted the dual horn set up and the problems started. Then by pure stupidity I plugged the washer bottle t connection into the horn t connection. After a lot of swearing and name calling ( at the car ) and it has to be said lots of sound advice from members on here, I copped on to my mistake.how ever the elation was short lived and the buggers still wouldn't work. After a lot of more fannying about with fuses popping and continuity testing,blah blah blah. I unplugged one of the dual horns and..........it worked! No more fuses blowing. It works. Perfectly. One single horn but not two.. Probably or rather most likely the dual horns were pulling too much juice thru the 8 amp fuse which promptly popped! Everytime . so now I will have to do what I should have done in the first place and fit a relay into the circuit. Simple ehh? More like simple mindedness on my part! Anyway lesson learned.......anyone know how to wire in a horn relay ???????? Man , I hate electric problems.

[steve bain]

Bliley. At least you know now! I would be going back to just one horn!

[type53b]

Steve I think you are right. What I might do is put the dual horns idea on the back burner for the moment, and crack on with the rest of small, tedious jobs that I need to get sorted to pass the test and back on the road.the tax disc that was on it when I bought it said november 1994. And I got it November 2009. So I need to get a move on,or it will stay in the shed forever.

[DT1]

Steve I think you are right. What I might do is put the dual horns idea on the back burner for the moment...

Since you have power to the horn, fitting a relay is fairly straight forward, you disconnect the live wire from the horn and use that to power the relay. Run a fused line from the battery to the relay and then to the horns. Make sure the relay is earthed and you are good to go and as long as the relay is waterproofed you can just leave it in the engine bay. It's a quick job.

[type53b]

I will get around to it eventually mate, right now I am just glad at least half of it is working! Lol

[type53b]

Steve I think you are right. What I might do is put the dual horns idea on the back burner for the moment...

Since you have power to the horn, fitting a relay is fairly straight forward, you disconnect the live wire from the horn and use that to power the relay. Run a fused line from the battery to the relay and then to the horns. Make sure the relay is earthed and you are good to go and as long as the relay is waterproofed you can just leave it in the engine bay. It's a quick job.

I got around to doing this and it was pretty easy as you said. So relay is wired up and the dual horns work perfectly as planned.thanks for all the advice!!