Subject: Re: [TR] TR4A Horn Question

From: Paul Tegler <[email-masked]>
Date: Wed, 27 Jan 2021 16:35:16 -0500

...not sure of the coil spec...but just for a reference....
a normal buss style fuse marked 'rating' is the spec holding current. 
(should not blow) It can take 10+ minutes to blow at 25% over the spec
The 'voltage' rating is the guaranteed 'disconnect blocking' voltage 
after the fuse blows.

So your horns must be spiking higher than the fuse rating to blow it quickly

ptegler

On 1/27/2021 3:50 PM, Dave Connitt wrote:
> Hi All,
> One of my winter projects is to determine why the horn fuse in my TR4A keeps blowing.
> I had installed a Advanced AutoWire harness during the restoration. The harness contains a 20 amp fuse for the horn. The horns are new as of the restoration. I went through the wiring harness and could not find a issue there so now I am looking at the horns themselves and that is where I need your help. I measured the horn coil resistance and it is 0.8 ohms in both of them. If I use 13.8 VDC as my battery voltage, I get 17.25 amps at the fuse which is too close to the 20 amp fuse rating in my opinion. If the resistance was even 0.9 ohms, the fuse current would be a little over 15 amps which would make more sense. Does anyone know what I should see as a horn coil resistance on a good horn?
> Thanks in advance,
> Dave Connitt
>
> Sent from my iPhone
> ** [email-masked] **
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Paul Tegler
[email-masked]  www.teglerizer.com

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From: David Friedlander <[email-masked]>
Date: Wed, 27 Jan 2021 16:43:38 -0500

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Dave;

I assume you've checked the ground wires for each horn....

Dave

On Wed, Jan 27, 2021 at 3:50 PM Dave Connitt <[email-masked]> wrote:

> I had installed a Advanced AutoWire harness during the restoration. The
> harness contains a 20 amp fuse for the horn. The horns are new as of the
> restoration. I went through the wiring harness and could not find a issue
> there so now I am looking at the horns themselves and that is where I need
> your help. I measured the horn coil resistance and it is 0.8 ohms in both
> of them. If I use 13.8 VDC as my battery voltage, I get 17.25 amps at the
> fuse which is too close to the 20 amp fuse rating in my opinion. If the
> resistance was even 0.9 ohms, the fuse current would be a little over 15
> amps which would make more sense. Does anyone know what I should see as a
> horn coil resistance on a good horn?
> Thanks in advance,
> Dave Connitt
>
> Sent from my iPhone
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/triumphs/[email-masked]
>

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<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:comic sa=
ns ms,sans-serif;font-size:large;color:#000099">Dave;</div><div class=3D"gm=
ail_default" style=3D"font-family:comic sans ms,sans-serif;font-size:large;=
color:#000099"><br></div><div class=3D"gmail_default" style=3D"font-family:=
comic sans ms,sans-serif;font-size:large;color:#000099">I assume you&#39;ve=
 checked the ground wires for each horn....</div><div class=3D"gmail_defaul=
t" style=3D"font-family:comic sans ms,sans-serif;font-size:large;color:#000=
099"><br></div><div class=3D"gmail_default" style=3D"font-family:comic sans=
 ms,sans-serif;font-size:large;color:#000099">Dave</div></div><br><div clas=
s=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Wed, Jan 27, 202=
1 at 3:50 PM Dave Connitt &lt;<a href=3D"mailto:[email-masked]">dconnitt=
@fuse.net</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding=
-left:1ex">Hi All,<br>
One of my winter projects is to determine why the horn fuse in my TR4A keep=
s blowing. <br>
I had installed a Advanced AutoWire harness during the restoration. The har=
ness contains a 20 amp fuse for the horn. The horns are new as of the resto=
ration. I went through the wiring harness and could not find a issue there =
so now I am looking at the horns themselves and that is where I need your h=
elp. I measured the horn coil resistance and it is 0.8 ohms in both of them=
. If I use 13.8 VDC as my battery voltage, I get 17.25 amps at the fuse whi=
ch is too close to the 20 amp fuse rating in my opinion. If the resistance =
was even 0.9 ohms, the fuse current would be a little over 15 amps which wo=
uld make more sense. Does anyone know what I should see as a horn coil resi=
stance on a good horn?<br>
Thanks in advance,<br>
Dave Connitt <br>
<br>
Sent from my iPhone<br>
** <a href=3D"mailto:[email-masked]" target=3D"_blank">triumphs@au=
tox.team.net</a> **<br>
<br>
et=3D"_blank">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://www.team.net/pipermail/triumphs" rel=3D"noreferr=
er" target=3D"_blank">http://www.team.net/pipermail/triumphs</a>=C2=A0 <a h=
ref=3D"http://www.team.net/archive" rel=3D"noreferrer" target=3D"_blank">ht=
tp://www.team.net/archive</a><br>
<br>
hs/[email-masked]" rel=3D"noreferrer" target=3D"_blank">http://autox.te=
am.net/mailman/options/triumphs/[email-masked]</a><br>
</blockquote></div>

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From: DAVID MASSEY <[email-masked]>
Date: Thu, 28 Jan 2021 01:15:37 +0000 (UTC)

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 Dave, if those are the old style Windtone horns, like the ones on my TR3, =
check the insulators on the relay mechanism inside the horns.=C2=A0 One of =
mine started breaking down and created a short to ground.=C2=A0 I made a re=
placement out of some modern thermoplastic and restored proper operation.
If that is a 20 amp SAE fuse 17 amps will be handled easily by the fuse.=C2=
=A0 It is rated to carry 20 amps continuously and will trip at 35 - 40 amps=
.
=20
Dave=20

=20
=20
-----Original Message-----
From: Dave Connitt <[email-masked]>
To: Triumphs <[email-masked]>
Sent: Wed, Jan 27, 2021 2:50 pm
Subject: [TR] TR4A Horn Question

Hi All,
s blowing.=20
stance on a good horn?
Thanks in advance,
Dave Connitt=20

Sent from my iPhone

Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archiv=
e

[email-masked]

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<div style="color:black;font: 12pt Arial, Helvetica, sans-serif;">
<div> <font size="3">Dave, if those are the old style Windtone horns, like the ones on my TR3, check the insulators on the relay mechanism inside the horns.&nbsp; One of mine started breaking down and created a short to ground.&nbsp; I made a replacement out of some modern thermoplastic and restored proper operation.</font></div>

<div><font size="3"><br>
</font></div>

<div><font size="3">If that is a 20 amp SAE fuse 17 amps will be handled easily by the fuse.&nbsp; It is rated to carry 20 amps continuously and will trip at 35 - 40 amps.</font><br>
</div>

<div> <br>
</div>

<div style="clear:both"><font size="4">Dave </font><br>
<br>
</div>

<div> <br>
</div>

<div> <br>
</div>

<div style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original Message-----<br>
From: Dave Connitt &lt;[email-masked]&gt;<br>
To: Triumphs &lt;[email-masked]&gt;<br>
Sent: Wed, Jan 27, 2021 2:50 pm<br>
Subject: [TR] TR4A Horn Question<br>
<br>

<div dir="ltr">Hi All,<br>
</div>

<div dir="ltr">One of my winter projects is to determine why the horn fuse in my TR4A keeps blowing. <br>
</div>

<div dir="ltr">I had installed a Advanced AutoWire harness during the restoration. The harness contains a 20 amp fuse for the horn. The horns are new as of the restoration. I went through the wiring harness and could not find a issue there so now I am looking at the horns themselves and that is where I need your help. I measured the horn coil resistance and it is 0.8 ohms in both of them. If I use 13.8 VDC as my battery voltage, I get 17.25 amps at the fuse which is too close to the 20 amp fuse rating in my opinion. If the resistance was even 0.9 ohms, the fuse current would be a little over 15 amps which would make more sense. Does anyone know what I should see as a horn coil resistance on a good horn?<br>
</div>

<div dir="ltr">Thanks in advance,<br>
</div>

<div dir="ltr">Dave Connitt <br>
</div>

<div dir="ltr"><br>
</div>

<div dir="ltr">Sent from my iPhone<br>
</div>

<div dir="ltr">** <a ymailto="mailto:[email-masked]" href="mailto:[email-masked]">[email-masked]</a> **<br>
</div>

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