Horn has no power

[Eighty5ov]

Hey guys. When I hit my grant horn button I don’t even get a click at the horn relay. Fuse is good. Any advice before I dig into it tomorrow ? I took it relay and put power to it and it was clicking. The first thing I do tomorrow is to take it out again and test to see if I got hot power going to it. Any advice is appreciated

 

[brooksman9]

The horn button completes the ground to the relay. Not the 12V+. Check for continuity rather than voltage coming back from your button.

 

[RustyPile]

First thing to check is the fuse. If the fuse is good, the following applies. The horn circuit works similar to the dome light circuit. The dome light bulb is "hot" all the time, the circuit has to be grounded for the light to come on. In the horn circuit, the relay winding has to be grounded to make the horn blow. Strange as it may seem, voltage appears on both sides of the winding and the ground side is looking for a ground. That ground is provided when the horn button is depressed. Remove the horn button and, ground one end of a jumper. touch the circular metal disk and the horn should blow.. If the horn doesn't blow, listen for the relay click. check for voltage at the horns while the disk is grounded. If voltage is present, the horn is bad. If voltage is not present, refer to the wiring diagram and check horn relay and its voltages. The orange wire is hot all the time. The black wire is the ground path back to the horn button on the steering wheel. The black wire w/green trace is power to the horn(s)

 

[Copymutt]

Heres a break out of the items under your horn button. Recently went thru this. Item 11 contains the spring loaded actuator to ground. It also cancels the turn signals. While Summit Racing has this & says compatible, it is not.
Wrong inside diameter and too shallow to get the shaft clip back on. Not sure who to recommend as I modified the SR. I’ve repaired a few horn actuators on different vehicles. Ball point pen springs and pop rivet collars are helpful.

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[Elliot W]

Couldnt agree more with @RustyPile 's response. I just had to do this on my truck after I replaced the turn signal cancel piece (part #11). Mine was missing a piece (I probably threw away thinking it was a bonus part and really only checked operation of the cancel aspect), so I had to fabricate a piece to work. More than likely its your fuse, if thats good, check the contact in the steering wheel, then check your relay and relay inputs.

 

[Eighty5ov]

The horn button completes the ground to the relay. Not the 12V+. Check for continuity rather than voltage coming back from your button.

How do I check continuity?

 

[Eighty5ov]

I have continuity in the steering wheel. Fuse is good.

 

[Eighty5ov]

I have no continuity at the relay or any power

 

[RustyPile]

I have no continuity at the relay or any power

I have continuity in the steering wheel. Fuse is good.

I think you may not understand the term "continuity".. Electrical work and problem solving is, to some, a mystery because the electrons flowing through all those wires are invisible. Unlike a coolant or oil leak, they don't leave a trail behind for one to follow. Go back and read post #3.. The procedure for checking is in that post. Follow the instructions. IF you don't have voltage on the orange wire at the relay, the horn will not work.. The horn fuse protects this wire.. IF the fuse is good, there is an open in the orange wire before it gets to the relay.

I repeat: Post #3 explains it all. Do the tests as indicated, and in the order they're listed.. You'll need two primary tools -- a wiring diagram for your truck and a volt meter of some sort.. If you still don't understand how the circuit works or how to troubleshoot it, I suggest you get some "hands on" help to aid you...

 

[brooksman9]

Mr Pile is correct. He describes it very well in that post. I was a little short on mine. It takes 12V dc to power the coil that closes the contacts on the relay. 12+dc is on one contact and the other side goes to the horns. 12v+ is also already present at the coil. When you push the horn button it completes the 12v- to the other side of the coil pulling in the relay to close the contacts. With your ohm meter check for continuity to ground on the negative wire to the coil when you push the horn button. An audible volt/ohm meter is good to have for this test. I have two of my vehicles that I have a separate horn button installed because the horn parts are missing at the button. Common for some of these older cars/trucks. I just tapped off a ground and tied into that wire. Walla! Noise. Good luck.

 

[Eighty5ov]

Thanks everyone for the help, I’ll use this information and see what I come up with.

 

[RustyPile]

Eighty5ov, this is not meant to be disrespectful or criticizing your choice of steering wheels. Grant has the worse designed horn mechanism on the market.. Very cheaply made and always problematic. That may be the root cause of your horn not working.

LeCarra has a great selection of steering wheel styles that are well designed.. The Lecarra wheel in my truck is at least 12 years old (that's how long ago I first saw the truck) and it still looks and works like new.

 

[Eighty5ov]

It’s all good man I appreciate any insight. It’s a horn how hard can it be right, it’s just the final thing to do for me to get it passed and on the road. I got the just of it all, and got power to the relay. No clicks. When I benchmarked the relay with 12 v it clicked. So I’ll ground it out and see if she honks.

 

[Matt69olds]

Find the turn signal switch connector. Find the black wire in the connector. Use a fused test light, ground the black wire. The relay should click, ideally the horn should sound. If so, the problem is above the turn signal connector (most likely in the wheel)

 

[Eighty5ov]

Ok fam. I’ve took the advice you guys gave and I have some results. I didn’t trust my relay so I did couple tests. Ran voltage to the hot and ground to get it to click and we had 12 v on the black green wire. So that works.

I then decided to watch a video on my non functioning horns. Very simple horns to fix so I had to rebuild one and got the other to work. Feel free to ask how.

So now I’m at Matty’s last post. I got functioning horns. Good relay. Good fuse. The orange wire is hot. We need to get from horn button to relay to ground and we are gold. So I’ll take off the grant, do the tests advised and hopefully figure this out