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TR6 TR6 horn button intsall

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brent615

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the new horn button and steering wheel (Nardi)are more of a challenge than expected to install. I finally got the correct adaptor to fit the TR6 and found the following:

1. beneath the hub adaptor there is a copper ring that is hot i.e. touch the ring and touch a grounded surface and get a shock. Pavlov was correct....I only did this three times before I stopped!

2. Install the hub adaptor which has a wire inside with a spring loaded lead that contacs the ring in #1 above and has a spade connector on the other end.

3. On back of hor button there is a spade connector male that is obviously meant for the wire in #2.

Connect all of the above and the horn does not work. The horn relay does not even click click as it had each time I shocked myself in #1.

The real question: Do the horn units serve as the ground for the circuit and therefore must be wired up in order for the horn button to engage the horn relay (clicking sound) or I am I missing a ground somewhere in/around teh horn button steering wheel?

Is that clear as mud?
 
I noticed that you made no mention of a "horn brush" to make contact between the horn button and the copper slip ring. Does the Nardi adaptor not work that way?
 
Oh, the "real question" I forgot. If the circuit is wired correctly you can activate the relay without having the horns working. And you'll hear the relay click. Once the points in the relay click closed, current can be delivered to the horns and they should sound if the horns themselves are properly grounded.
 
Does that system still connect to ground thru the wire at the steering box, or do you perhaps have to wire a separate ground?

Just as an aside, I'm surprised that you got a shock from an unamplified 12 VDC. Don't think I've ever experienced that.

Tom
 
It sounds like you mave have lost the ground to the steering shaft itself. Instead of shorting the ring to the outside of the column or other ground point, try shorting directly to the steering shaft. If you don't get a click, that's where your problem lies. I suggest not using your fingers to provide the short circuit!

Randy
 
if i ground the wire on the hub adaptor the horn relay clicks. i think i need to connect the horns themselves. i know they work. i was thinking that maybe the horn units were the ground in the circuit and the button simply completes the circuit when depressed....does that sound right?

i'll have to admit the electrics are not my strong suit. what i have done to date has been alot of trial and error
 
I do not remember any horn circuit that uses the high side (+) to complete the circuit at the button... All Triumphs and all domestic cars ground the low (-) side of the circuit at the button. Moreover, not all TR6's have a horn relay... my 69 is direct wired. This car is unmolested so I believe it never had a relay. If your car has no relay, then no wonder you were shocked. Given the circuit is in tact and the horn windings are good, you became ground for the stored potential in those coils...so you were shocked. So, I believe you may not have a relay on yours. The horn wires are lavender in color, so They should be easy to trace. Also make sure the ground wire for the steering rack is there and really grounded... Check the flex joint and make sure the jumper wire is across it... if not, your horn won't work!
 
Yes, the horn should be grounding on the low side of the relay. 1969 was the only year without a relay on the TR6. As a 71, there should be a relay.

Dan Master's wiring diagrams are a good way to at least map out where the problem might be:

TR6 diagrams

Is the hub adaptor attached to the steering shaft now? By grounding the wire to the adaptor, you should be grounding to the adaptor, then into the steering shaft itself, then ultimately to the frame at the steering rack. Take Sherman's advise and check for a ground wire at the flex joint on the steering shaft, and at the steering rack.

If you hear a click when you ground to the adaptor, but not when you ground to the center shaft it is a little confusing - you may actually be grounding the adaptor to the steering column itself which is something you will need to fix also, otherwise the horns will probably go off everytime you turn the wheel without hitting the horn button.

The horns should be hooked to a Purple and yellow wire which attaches to terminal C1 on the relay. They also have black ground wires which ground somewhere on the frame.
 
<span style="color: #000000"><span style="color: #33CC00">Thanks. As is, there is no click when I ground the horn wire to either the steering wheel hub or the shaft. Can you give me a little more detail on where to look for the grounds? Am I looking in the cockpit or in the engine compartment?

I think I am getting close. Thanks for everyone's input!!!</span></span>
 
You need to look at the steering shaft in the engine compartment. First, look at the upper rubber coupling - there should be a ground wire connecting the upper and lower shafts, quite often it is missing. No wire, no ground.

If you have that, check down by the rack itself, I believe there normally is another ground wire from the rack to the frame or engine.

Ahead of that though, if you have the horns hooked up, and you ground to say the bulkhead or instrument panel, you should get a click on the relay and a toot on the horn. If not, a bad ground may not be the only issue.
 
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