mobilehippo Posted July 30, 2014 Author Share Posted July 30, 2014 Hazards are working... I'll trace the wires... I can't imagine it getting snagged by a bolt since I didn't add anything since the last time it was working... though maybe it's just old... Quote Link to comment Share on other sites More sharing options...
zero Posted July 31, 2014 Share Posted July 31, 2014 Hazards are working... I'll trace the wires... I can't imagine it getting snagged by a bolt since I didn't add anything since the last time it was working... though maybe it's just old... If I'm being redundant - I apologize - but . . Have you tested those two wires that attach to the horn under load and know, for sure - that the positive unswitched wire is the culprit? Ocam's razor dictates the problem is apt to be where the moving parts are. Only moving parts are in the steering wheel and inside the horn and you've ruled out the latter. Quote Link to comment Share on other sites More sharing options...
mobilehippo Posted August 2, 2014 Author Share Posted August 2, 2014 Alright I found this in my Toyota pick-up manual that I downloaded some time ago. And I found this picture below showing how the horn circuit works. I can't figure out why my horn isn't working. I thought the culprit is the wire going into the horn, but according to this diagram, if Im reading any power going into the wire at steering wheel for the horn buttons, then power should be circulating through the whole system. I've checked for corrosion and that doesn't seem to be the problem..... I have definitely tested the horn and hardwired it to the battery and it does indeed honk. I really don't know what could be wrong with this whole system. This is very frustrating. Quote Link to comment Share on other sites More sharing options...
zero Posted August 2, 2014 Share Posted August 2, 2014 I definitely do not think the steering wheel is the culprit because I have test the power in the wire there where it grounds, and I read 12v. I have also just manually put the wire straight on the ground while the horn is connected and nothing happens. I mean maybe it is the fuse. My fuse box has 7 fuses and it looks like many of the same things share the same fuse. Does anyone know what fuse goes to horn? Stop lights and horn share the same fuse. If the fuse that powers the horn was blown - you'd have no stop lights. You say you grounded the wire. Which wire? The wire coming out of the wheel? Or the wire before it gets to the wheel? Voltmeter for these test purposes is useless. Not unless you take readings under load and there is no load since the horn is not working. Just test AT the horn. It only has two terminals. Try running jumper wires from the horn harness plug (after it's unhooked), one at a time. First - hook the positive side of the harness to one terminal on the horn via a jumper. Now just ground the other horn terminal. If it now beeps - you know the problem is in the horn-button-ground circuit. If not? Second - leave the one terminal grounded on the horn. Now run a power wire from anywhere that gives you 12 volts positive. if it works that way - you know the positive power wire that is supposed to be "hot" all the time , is not. Quote Link to comment Share on other sites More sharing options...
Donnie Posted August 3, 2014 Share Posted August 3, 2014 I've not much to add here since I took an a$$ whippin' back when I came down on poor Fred who was only trying to help me............. I think Maris covered it pretty well. Especially in his post # 24....image # 7.............this area is problematic in pre '79 trucks........Donnie Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 3, 2014 Share Posted August 3, 2014 Alright I found this in my Toyota pick-up manual that I downloaded some time ago. And I found this picture below showing how the horn circuit works. I can't figure out why my horn isn't working. I thought the culprit is the wire going into the horn, but according to this diagram, if Im reading any power going into the wire at steering wheel for the horn buttons, then power should be circulating through the whole system. I've checked for corrosion and that doesn't seem to be the problem..... I have definitely tested the horn and hardwired it to the battery and it does indeed honk. I really don't know what could be wrong with this whole system. This is very frustrating. Your diagram is correct how ever the problem is that you have said there is no power to the horn so if there isn't it can't feed back to the horn contact on the signal switch. The haz lights are on the same circuit same fuse if you believe one of the diagrams so some where between the fuse and the horn there is an open circuit be it a rotted connection or a broken wire, If you are using a DVM it draws no current so it can not load a circuit and even the slightest connection will carry voltage a dvm can read but no current if you have a test light that would give you a better ideal as to what is going on because it will load a circuit and if the connection is faulty it won't light or light very dimly. Quote Link to comment Share on other sites More sharing options...
Donnie Posted August 4, 2014 Share Posted August 4, 2014 Sorry team, I must have glazed over the part where he said "there is NO power TO the horn....I thought he was having a ground problem..Too tired & I just didn't read that part................Donnie Quote Link to comment Share on other sites More sharing options...
zero Posted August 4, 2014 Share Posted August 4, 2014 We are talking about a simple device with only two terminals. When the horn button is pressed - the horn is either getting 12 volts neg to one terminal and 12 volts positive to the other, or it is not. When it comes to diagnosing electric problems - this is about the simplest scenario there is. I think as we all comment and discuss it - it just gets more convoluted. Two terminals. One gets 12 volts neg, and one gets 12 volts pos. If not - no "beep." Quote Link to comment Share on other sites More sharing options...
mobilehippo Posted August 24, 2014 Author Share Posted August 24, 2014 Does anyone know if there is an inline fuse in the horn system? If so where I would be able to check it? Thanks! Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 24, 2014 Share Posted August 24, 2014 No inline fuse unless some one added one. Same fuse as the hazard warning lights. Quote Link to comment Share on other sites More sharing options...
mobilehippo Posted August 28, 2014 Author Share Posted August 28, 2014 I would like rewire my horn because I can't seem to find where the the wiring is bad on my horn. Anyone have any suggestions on the best way to do this. I should just be able to run another line from my fuse box located under my steering wheel. Or I could run one from the battery but that doesn't seem as good of an idea. Any guidance would be much appreciated! Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 28, 2014 Share Posted August 28, 2014 Why don't you just make a jumper wire up and connect it to the horn and see if it blows when you push the button? If it does make up a proper wire and install an inline fuse. Quote Link to comment Share on other sites More sharing options...
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