Stumped by Centech Horn Wiring and Aftermarket Wheel

[sedav1]

I have searched dozens of posts without finding an exact answer so I am hoping you all can help me once and for all.

I am wiring up my steering column and my horn is killing me. I have looked at diagrams and read the manual over and over but I just can't seem to get it to work.

Everything else is functioning properly.

I have a 73 column with TBP Column wires, a Centech Harness and a Grant wooden wheel. It looks to me that the horn with the wheel grounds the circuit but I just can't figure out the wiring combination.

From the TBP Column I have a Yellow wire and a Blue/White wire for the horn.

From the harness I have D =Horn Power In, E = Horn Switch Out (Single Wire) and the G = Horn relay

In the engine bay I have a singe Horn(Yellow) on the DR side and a Horn(Yellow) & Grnd on the passenger.

I know centech supposedly has a relay built in but I am drawing a blank on how to wire it up with the colors above. I have looked at horn relay diagrams at length but I am hoping someone has wired this up before.

Hopefully its just something simple I am missing.

Thanks for your help.

Steve

 

[Pearlcoat]

Funny you should post this, we are having the same problem. I'm going to watch for an answer from someone who has figured it out. Thanks!

 

[krashnpa]

Not sure if it helps, but on my harness (non centech), the ground from the horn switch energized the coil side of the relay which closed the switch side of the relay to send power to the horn in the engine compartment. The horn was grounded directly in the engine compartment and the harness only sent power.

With all those wires, you may have either option, run power through the switch or use the switch to operate the relay, which is usually better. If you have a multimeter, you can test for ground when the horn button is pushed /closed circuit between the wires when the horn button is pushed. Usually you have to make sure the horn button doesnt ground if you do not use the relay. Otherwise if you run poower through the horn and hit the buttton you'll get a short to power.

Found this, seems to explain it -

http://classicbroncos.com/photos/showphoto.php?photo=4173

 

[sedav1]

Thanks for the effort but that's where I am stuck at. I have practically memorized that diagram.

If I run yellow(horn) to D and then Blue(horn) to G (relay) and wire up the horn to the yellow horn wire in the engine bay I get nothing. I have to be missing something.

I understand how the relay is supposed to work but I am having difficulty decoding how the centech harness should be hooked up because of the two options.

 

[krashnpa]

The way I read it is this- if you're using both wires, you dont use the relay. The horn becomes a power switch, nothing more. You have a power in (yw) and power out to the horns (bl/yw) that connect to the column yw and bl/white at the column. In that case, you may need to cut the spring in tbe horn button so it doesnt ground, but you can call Tom's to confirm.

If you use the relay, only one wire will be used from the column (connect to G in the connector) and you do nothing with the horn button spring and the wire you dont need from the column the harness. All you have to do is figure out which wire from the column grounds when you press the horn button, and it could be both.

Most horn configs that I've seen that involves a relay always used the horn button as a ground to the coil on the relay. Can you test the bl/wh wire and then the yellow wire to ground to see if you have 10 ohms or less/continuity to ground when the horn button is pushed? Whatever wire provides ground (might be both) is the wire you connect to terminal G.

 

[sedav1]

Thanks for the additional info. I am following you with that part but what about the rest of the circuit?

Based on the relay diagrams Power goes to the relay, relay then goes to the horn button which grounds the circuit and activates the switch. I can mess with the wires and figure out which one to use.

The big question is what wire is the relay to horn wire that I connect the horn up to. The centech harness is all wrapped so I can't trace backwards. I have two yellow wires labeled horn. One on the DR and one on the Pass Side.

I was hoping someone has dealt with this before and could just chime in.

I have an extra relay switch so if I can't figure it out I may just wire it up myself. I would really rather use the harness though and solve this.

 

[krashnpa]

I think you're getting somewhere. My harness was prewired for the relay. I connected the ground wire from the relay to the horn button and the hot wire to the horn in the engine compartment. If you run the horn button wire and connect to the relay, have a helper push the horn button and test for power in the engine compartment. Also make sure you did not blow the fuse messing around.

If you don't have a test light or a multimeter, I'd invest in one or both. You can get one at Harbor Fright for a few bucks and will save you the aggravation of guessing which wire does what.

 

[sedav1]

It works!

Got the horn to work.

From the horn button, wired up the yellow wire (horn) from steering column to G connection (Horn Relay) on the Centech harness. I did not use the other horn wire (blue/white) and just plugged it into a non used port in the harness.

Connected the horn to the Drivers side yellow (horn labeled) wire and grounded to the body.

Works like a charm. Thanks for the help.