Seaside Pete Posted October 28, 2014 Report Posted October 28, 2014 Hi. I am new to this forum and I hope someone can help. I am in the UK and have just purchased a 1947 4dr special deluxe that arrived in the UK this August. It has been changed to 12v NEG earth (well almost as some things have been dis connected.) I am gradually changing the wiring and including adding fuses as the old stuff is not in very good condition. The problem I am having is with the horn relay. I have purchased a modern 4 terminal relay and have wired it as per attached diagram (which I found on the net) however I do not seem to have a live feed from the horn button? Before I took out the old relay I used a test light and there was a live feed. When I replaced the horn button feed with a direct feed from the battery the horns work fine. looking at the wring diagram there seems to only be one wire from the horn button how is the horn button fed? Thanks in advance Pete horn relay.doc Quote
Merle Coggins Posted October 28, 2014 Report Posted October 28, 2014 Your horn button provides the ground to the circuit, not the power. Give your relay a constant power supply and connect the ground side of the relay (85) to the horn button. Merle Quote
Don Coatney Posted October 28, 2014 Report Posted October 28, 2014 This might or might not help. Quote
Seaside Pete Posted October 28, 2014 Author Report Posted October 28, 2014 AH, I did wonder if it was a make and brake earth. Thanks I will give it a try. Pete Quote
_shel_ny Posted October 28, 2014 Report Posted October 28, 2014 (edited) I can not open your diagram. Here is a typical hook up for our vehicles. As said, horn button provides ground (earth) Edit: They were set up so that the horn only worked with the ignition on. You can wire it so the relay has power all the time so you do not have to turn the ignition on first when someone is about to back into you and you want to give a warning honk. Edited October 28, 2014 by shel_ny Quote
Niel Hoback Posted October 28, 2014 Report Posted October 28, 2014 If you wire power to it all the time, it will run your battery down. Quote
Merle Coggins Posted October 28, 2014 Report Posted October 28, 2014 If you wire power to it all the time, it will run your battery down. Why? That would only be true if the horn were sounding all of the time too. Until you press the horn button and complete the circuit there will be no current flow. My truck's horn relay is powered directly from the BAT terminal of my voltage regulator. This is how it was done on the trucks and it has no effect on battery life. Merle 1 Quote
Niel Hoback Posted October 29, 2014 Report Posted October 29, 2014 Merle, you are right. Seems I type before I think. Sorry. Quote
Seaside Pete Posted October 29, 2014 Author Report Posted October 29, 2014 Hi all Thanks again for the info it works now but I had to add a jumper lead from terminal 30 to 86. I am running it from the Battery side through a fuse. On another point, as you can imagine it is hard getting parts over here everything has to be shipped over. I need to get some trim clips for the wide chrome trim that goes along the sill under the doors, There seems to be all types of trim clips available but I can't find any of these. I would be grateful for any help. Thanks Pete Quote
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