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

William J catnine09 at dslextreme.com
Sat Nov 11 19:46:23 PST 2017

 I don't know Dave.

 I know there is a wire that jumps the steering coupling. The odd thing is 
the horn works if the car is running even at idle when the voltage is low.

 When I look at the 73 schematic in the Bentley it only shows one brown wire 
which is from the turn signal switch that activates the high/ low beam relay 
and that works . I checked that brown wire at the column connector and it is 
a chassis ground. I also had a jumper to the horn brown ground at the horn 
with that wire unplugged from the horn and found no continuity to the only 
brown wire to the turn signal .

 I can see through the gap between the steering wheel and column which is 
about 1/16" and can see the horn contact ring on the wheel and can see a 
contact of brass on the turn signal switch . I placed paper towel over a 
shaved down chop stick with contact cleaner and rotated the wheel until it 
came out clean.

 The steering wheel has never been off and since it's that deep collapsable 
type I don't have a puller to reach down in there and the wheel won't budge 
with the nut loose and I'm afraid I'll break it banging on the back .

 What I don't know is how the brass turn signal contact makes it's contact , 
it's not like the 72 spare I have where the brown wire is connected to that 
brass contact. The 73 is completely different it just has the one brown lead 
and a brown white which are the high low beam relay. There is no brown to 
the brass T/S brass deal that I can tell . From the 73 schematic in the 
Bentley it seems the 4 way flasher switch controls the turn signals yet I 
see no actual turn signal flasher switch or how it connects to the 4 way . 
It's possible that brown wire also connects to the brass wiper in the T/S 
switch yet it's a chassis ground. If it connects to the brass wiper which 
contacts the wheels ring that ring then has a wire that connects to the horn 
pad which does not complete the ground until the pad is pushed down. That 
would work yet the Bentley does not reflect this.

 When I had the fuse box down and work the turn signals the tall flasher  on 
the far left works at the same time as the high/low beam relay. If I pull 
the flasher out the high low no longer clicks along. Some how they work 
together. I know the T/S flasher and 4 way are the same unit.
----- Original Message ----- 
From: "Dave Hall" <dave at hallvw.clara.co.uk>
To: <type3 at vwtype3.org>
Sent: Saturday, November 11, 2017 6:12 PM
Subject: Re: [T3] On a 73 T-3 SB. The damn horn circuit.

> 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.
> Dave,
> 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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