Horn Problems

[79jasper]

Just try swapping the relay with a different one.
You know, just in case.
Try the connector on the column.


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[Nut Tree]

Swapped with a known good one and it doesn't change anything. When you pull the cover off the steering wheel there is a female plug with 3 small male pins inside. I tested each pin and non of them had any voltage with the key on or off.

 

[gandalf]

OK, now I'm at a loss. The fuse shows 12v in and 12v out with full continuity. I pulled the relay and tested it according to the included link and it tested good as well.
No what?

http://easyautodiagnostics.com/ford_relay_tests/relay_bench_test_2.php

Tell us a bit about how you tested that fuse. 12v in/12v out is not the way I'd normally test a fuse. Did you test that with the fuse in place, or did you pull the fuse for the test. I would usually test the fuse for continuity, using a multimeter. After all else is done, and with all the trouble you're having, I'd start checking continuity on all the wire in the horn system. With no power getting to the horn button, and the fuse good, I'd say that there must be a break in the circuit between the power distribution box and the horn button. Check continuity on all sections, tracing that wire system, and check continuity across all connections. Also, at each test point check that you still have 12v.

Electrical problems in a vehicle can be a real ***** to track down. Best of luck.

 

[Nut Tree]

I put the ground probe of my meter on the negative battery terminal and the positive to one side of the fuse while it was in the box and got 12v. Then I touched the positive probe to the other side and got 12v. Then, just to be sure I was doing it right, I pulled the fuse and looked at it to see if it looked burnt/broken. What your saying makes sense. If I have power to the fuse and the relay tests good there must be a break between that box and the steering wheel. I'll try to track it down tomorrow. If I can't find it, can I just run a wire from the terminal on the relay up the column to the horn switch and bypass the factory stuff?

 

[79jasper]

You should have a connector along the column somewhere.
Could very well be unplugged.


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[jim x 3]

If I have power to the fuse and the relay tests good there must be a break between that box and the steering wheel. I'll try to track it down tomorrow. If I can't find it, can I just run a wire from the terminal on the relay up the column to the horn switch and bypass the factory stuff?

NutT: Yes you could, if you truly replace the factory wiring 1:1 (which at this point doesn't seem 100% certain). But it would be better to find and fix the real problem rather than bypassing it. If you need to run a new wire you will be tracing that route path anyway. Assume (as you have) that there is a broken power wire between fuse box and steering wheel. If you take the easy way out and bypass, that broken wire is still there and powered. If/when it vibrates and giggles and eventually touches chassis ground, it will blow the horn fuse. You will lose the horn again (and everything else on that fuse) and the problem to find and fix is as tough as your current problem. And if you have made undocumented changes to your wiring (and not just this one but many others for other problems), you can't rely on the Ford wiring diagram to troubleshoot. OK, so maybe the latent defect would never cause a problem (until you sell the truck to some other poor sucker), but I would still recommend that you find and fix the real problem now.

Good luck.

Regards,