thirdangle Posted September 29, 2013 Report Share Posted September 29, 2013 Hi. I'm having problems with the horn operation on my TR6, seemingly depending on how tightly the (inner) steering column clamp is bolted up - the horn either does not operate at all, operates constantly, or comes on when I turn the steering wheel I've replaced the horn push, slip ring & spring plunger & had the steering column in pieces to ensure the rubber column joint jump overs are ok. Still no joy. Clearly the horns do work as earthing the spring plunger to the chassis with a wire jumper activates them. I have a Moto Lita wheel fitted. Well I am now running out of patience with this issue & with the MOT looming I am thinking of temporarily using a seperatly wired switch (there is an existing unused switch which the previous owner fitted as a cooling fan manual override but a new electric fan has made this switch obsolete). I assume I can simply run a wire from the outlet side of the fuse in the fuse box (there is a spare terminal) to the spare cockpit mounted switch, & then back out to the horn live terminal. Does this sound an electrically safe solution & what rating should the wire be? If there are also any suggestions as to how to get the original system working again I'd also be happy to hear that as having spent many, many hours on this 'simple' issue I am get pretty frustrated with it. Many thanks in advance for any help & advice. Quote Link to post Share on other sites
RobinTR6 Posted September 29, 2013 Report Share Posted September 29, 2013 is the steering wheel boss clear of the outer column cowl, I recall that this caused a similar problem , i.e the boss was touching the outer column shroud when the wheel was turned. Just a thought Quote Link to post Share on other sites
TR NIALL Posted September 29, 2013 Report Share Posted September 29, 2013 is the steering wheel boss clear of the outer column cowl, I recall that this caused a similar problem , i.e the boss was touching the outer column shroud when the wheel was turned. Just a thought Yes I also found that that is a problem,the Steering Wheel and Boss sits to far down on the Splines and catches the bottom Shroud. Quote Link to post Share on other sites
TR Mitch Posted September 29, 2013 Report Share Posted September 29, 2013 (edited) I assume I can simply run a wire from the outlet side of the fuse in the fuse box (there is a spare terminal) to the spare cockpit mounted switch, & then back out to the horn live terminal The horn button in the steering boss completes the connection from the horn (permanent live) to ground, so the switch is just a connection to earth/negative/body. Your suggested method would not work as the horn already has a 12v feed to it. It is different to the lights, for example, where you are feeding a switched 12v to the device. The horn is electrically "back to front" in this respect. My suggestion would be to find the bullet connector that is the horn connection in the loom just under the dash (purple & black wire in some diagrams). Pull this apart then make up a new lead (bullet termination into a bullet snap connector with your existing horn wire) off to a momentary push button switch with the other side of the switch down to the chassis or convenient negative connection somewhere. Example switch that could be mounted in one of those under dash right angle brackets. Vehicle Wiring Products sell all the bits you need. I don't know if the TR6 has a horn relay as standard. If so, any momentary push button switch will do as current through it will be minimal. If it doesn't have a relay, then a 10A switch will be more than enough. Edited September 29, 2013 by TR Mitch Quote Link to post Share on other sites
tthomson Posted September 29, 2013 Report Share Posted September 29, 2013 One of the problems you might encounter with earthing the steering column is when the steering box on the rack is not earthed. The rest of the steering column may have the connections across the rubber doughnuts, but the steering box also needs to be connected to earth. There is a standard braided connection that is available for this, it is slightly longer than the ones for the rubber doughnuts. Without this, the horn will only work if your steering wheel boss scrapes metal on the column shroud. Use a multimeter on Ohms to see if there is a connection between the column and the chassis. This will show clearly if this is a problem or not. The reading should be near on zero Ohms for the full operation of the steering wheel. If it is open circuit at any point or has a reading higher than 3 or 4 Ohms then there is either a missing or a bad earth connection. You can also test this using a bulb and battery to test the connection. Good luck TT Quote Link to post Share on other sites
Bill Bourne Posted September 30, 2013 Report Share Posted September 30, 2013 Just a thought I had a similar issue with my horn coming on when I turned the wheel. After looking and looking - taking apart and putting it all back together 2 or 3 times, I eventually found the fault - It turned out to be, that the soldered connection to the slip ring (the purple wire underneath) was touching the housiing sometimes under lock. I bent it back a touch - no problems since. Bill Quote Link to post Share on other sites
Johncracknell Posted September 30, 2013 Report Share Posted September 30, 2013 Had the same problem on mine.. Fitted a good earth strap from the chassis to the rack... Job done !! Quote Link to post Share on other sites
thirdangle Posted September 30, 2013 Author Report Share Posted September 30, 2013 Many thanks for all of the helpful replies & suggestions. I'll have another go next weekend & see if I can get the original system up and running - steering wheel boss and earthing from rack to chassis are two things to zero in on, if no joy then I'll use a momentary switch as suggested, Cheers, Ian Quote Link to post Share on other sites
thirdangle Posted April 22, 2014 Author Report Share Posted April 22, 2014 Hi All. Due to time constraints with working away from home, I have only just got around to addressing the issues with my faulty horn - so I wanted to give the forum, & in particular those who responded to my initial question, an update. The problem lay with both the soldered tab on the brass ring which I simply bent back a little, & the Mota Lita boss touching the shroud which was remedied by filing back the underside of the wheel boss. Many thanks to all those who kindly replied with their thoughts & suggestions which once again underline the immense value of this forum & it's contributions Quote Link to post Share on other sites
RobinTR6 Posted April 22, 2014 Report Share Posted April 22, 2014 Beep, beep, well done, and can't agree more. Quote Link to post Share on other sites
ap20 Posted May 22, 2014 Report Share Posted May 22, 2014 Hi Everyone, Curiously my horn has just stopped working-no obvious idea why and just before the blasted MOT. The horn will work when I push down hard on the steering wheel and will then work again by pushing on the usual horn push. After a while the horn push will not work until I push down on the wheel and the cycle continues? I have checked the earth straps and I can see them all accept the one at the bottom on the steering rack, so maybe it is missing? Can anyone let me know how exactly do you fit a new earth strap, I just cannot see where it fits? All ideas, photos gratefully accepted. As an aside-I think! I have found a purple wire with an O ring connector dangling behind the dash-it does not seem to be live any ideas what this might be off? Thanks in anticipation, Andrew. Quote Link to post Share on other sites
RobinTR6 Posted May 23, 2014 Report Share Posted May 23, 2014 Behind the steering horn button is a brass/spring contact pin, It makes the connection between the horn slip ring (brass circle behind the steering wheel and the steering column via the steering wheel. Sounds like the spring or contact is stuck or broken so only works when you push down on whole steering wheel. Take off the horn button and remove the pin and inspect , sounds like thats the problem from your description Quote Link to post Share on other sites
KOB Posted May 23, 2014 Report Share Posted May 23, 2014 I often wonder on cars fitted with overdrive switch on the column whether there is pinching of the cables in the duct that conveys them along the column Quote Link to post Share on other sites
Denis Posted May 23, 2014 Report Share Posted May 23, 2014 That's what happens when you fit a none standard Steering Wheel and Boss! You could always refit the original back on for the MOT ! Quote Link to post Share on other sites
ap20 Posted June 10, 2014 Report Share Posted June 10, 2014 Thanks everyone for your recent and past help, what a forum this is! totally brilliant. Managed to get it working although entirely not sure how, but passed the MOT-happy days! Best Andrew Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.