[T3] On a 73 T-3 SB. The damn horn circuit.

Dave Hall dave at hallvw.clara.co.uk
Sat Nov 11 18:12:25 PST 2017

You've probably got a high resistance in the ground return (brown wire) which connects to the brass horn ring on the steering wheel via the front axle and the link across the steering coupler. 
With ignition on, use a wire to earth momentarily to the axle beam. If the horn sounds, try it on the link across the coupler, and on the column itself, until you isolate the area with a high resistance, and clean it carefully.

It may well be the coupler bolts are corroded, or the link wire, or maybe the steering box itself not making good contact with the beam.
If you have the steering wheel off, check the brass ring and contacts are clean. There's also a wire connection on the steering wheel to check, and contact pins with insulating washers.

Hope you find the problem.  I spent hours looking for a similar problem on my '71 and while there was a bit of resistance across the steering box, I ended up putting on a spare horn in desperation,  and that worked well enough for the annual test.

From next May, we no longer need to have an MoT test on cars over 40 years old in the UK. I think I would still want a second opinion from a mechanic with a ramp.
UK VW Type 3 and 4 Club.

-----Original Message-----
From: "William J" <catnine09 at dslextreme.com>
Sent: ‎12/‎11/‎2017 00:06
To: "type3 at vwtype3.org" <type3 at vwtype3.org>
Subject: [T3] On a 73 T-3 SB. The damn horn circuit.

 I have battery voltage at the horn ign on , if I remove the brown wire on the horn and use a jumper from the horn to the bumper the horn sounds loud. Simple little test. 

 If I connect the brown/ground back on the horn , key on and push the horn pad I get this tiny bleep . For some insane reason if the engine is running the horn works fine using the horn pad. 

 I looked at the Bentley and it shows no connection to the T/S switch . It shows the horn power off fuse 11 Bk./Yel  the ground brown then the horn pad a thin black line suggesting a chassis ground like you see for the fuel gauge to tank then a brown jumper across the steering coupling . 

 I removed the small cover under the column for access the the T/S plug . I see one brown wire , With the connector unplugged on the dash harness end that brown wire is direct to the chassis it does not go to the horn ground brown wire.

 I know the wheel has a contact ring and the T/S switch has a contact, 2 brass wipers.  

 I have a T/S / wiper switch off a 72 and I can see a brown wire on the 2 brass wipers yet it has more connectors, it's not the same. It's brown wire is not in the same spot on the plug.

 What am I missing here? I know the pad has 4 contacts with a wire that connects to the wheel contact ring , this makes and breaks contact from the pad to the ring at the base of the steering wheel . I know the brown wire from the T/S switch is direct to the chassis and does not connect to the horns brown wire because I get no continuity . 

  If the T/S contact goes to chassis ground from it's brown wire all I see in the Bentley for a brown wire to the T/S switch is for the headlamp dimmer which is a chassis ground for the dimmer relay. I don't see the T/S switch just the emergency flasher sending power to the front and rear turn lamps and it's on/off switch which works on 2 different fuses depending whether on or off. 

The Bentley also shows a single connector with only the horn brown ground wire under the dash I can't find it. 


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