Volvo P1800 Horn Problem PLEASE Help

[jimmyjam]

Please could someone help me as my car has nearly received my foot a
few times in the last few weeks. Its a horn I am fitting to my Volvo
p1800s 64. The original one is not working so i got another original
classic type horn, which was also tested in the shop and works. I
have mounted it where the other one was and I am also using the
metal bar behind it from the old horn to create an earth. Can
somebody please please tell me what colours go to the relay of the
horn and what colours go to the horn itself. I have looked at my
manual 100s of times and cannot make head or tail from it. As
mentioned I have a 64 and even though my manual shows three horns
surely I can install just one. Would really appreciate any help, as
i have nearly finished my project and I am not going to let some
stupid horn stop me. The numbers on the bottom of my relay are: 85,
86, 87 and 30. PPPPllllleeeeeeeaaaassseeeeee help me. Thanks
everyone. Jimmy UK

[mike gilbert]

Jimmy, the problem is that your car originally had three horns ( a town and country system) with individual wiring for each system. One went to the button on the steering wheel and one to the stalk on the indicator column. Now you have only fitted one horn, which wiring system are you using? Later cars with one horn system simply had a permanent live feed from the fuse box to the horn and an earth wire from the horn to the button on the steering wheel. Pressing the button earthed the earth wire to the steering column thus completing the circuit and sounding the horn. Rather than messing about with ancient relays, if you want to get the car on the road and are only using one horn, find the permanent live going into the relay and just route it direct to the horn. Than make sure the earth wire from the horn attaches the one going up your steering column (starting at the steering box) and it should work. If all else fails and you just want an MOT, run a live to the horn via an additional switch on or under the dashboard. Earth the horn in the nose cone and you can activate it via your additional switch - very simple and something I've done when the horn button mechanism is knackered/missing.
Mike.

[jimmyjam]

Thanks for the great advice mike, I will hook it up this way. Simple and effective. thanks Jim.

[night owl]

if new horn is more powerful and draws a large amount of current, larger current then an original single horn, then you will require a relay to help cope with this current draw.