[TR] TR2-3 electrical melt downs

[Don Hiscock]

Jonmac, I'm guessing your recollections of enhanced wiring in Italian and
Swedish Triumphs dates from your time in export sales in the 1960s, yes?
Do you have any ideas what models might have been covered?  Did the
addition of a lot more fused circuits go back as far as the TR2-3A models?

Thx,

Don

On Wed, Jun 24, 2020 at 11:42 AM Don Hiscock <don.hiscock at gmail.com> wrote:

> As usual, Jonmac's recollections are gold dust.  I hoard every scrap!
> (Thanks for 'em, John!)
>
> Does anyone have an Italian TR2-3A wiring diagram?  These must have
> existed originally, yes John?
>
> Rdgs,
>
> Don
>
> On Wed, Jun 24, 2020 at 11:01 AM John Macartney <
> John.Macartney at ukpips.org.uk> wrote:
>
>> I think Dave Massey is spot on in highlighting the things that can go
>> wrong with old looms. He’s also correct in saying the cars were built to a
>> budget and I’d add they were never built to last as long as so many have.
>> Ten years was the engineered life expectancy. Dave is also prudent to
>> comment on the very limited number of fuses for the US market. However,
>> it’s worth pointing out that in the days of yore, cars bound for Italy and
>> Sweden had completely different looms. IIRC, Italy spec cars had 12 main
>> fuses and Sweden a few less. Sweden also banned the plating that was used
>> on all hardware and fasteners and insisted on another form of plating.
>> Trouble is, I can’t remember what it was now. So, if you’re planning on a
>> new loom, get one made in Italy to original spec. Magneti Marelli used to
>> have a subsidiary that made them.
>>
>> Jonmac
>>
>> At the Battle of Waterloo, 1815:
>> Lord Uxbridge:  “By God, Sir - I’ve lost my leg”
>> Duke of Wellington: “By God, Sir - so you have!”
>>
>>
>> On 24 Jun 2020, at 15:52, bill beecher <notakitcar at yahoo.com> wrote:
>>
>> I counted, I only have two(2) fuses on my ‘58 TR3.   Where might the
>> other be?
>> Thx,
>> Bill B
>> TS30800L
>>
>> Serenity Now......
>>
>> On Jun 24, 2020, at 9:38 AM, DAVID MASSEY <dave1massey at cs.com> wrote:
>>
>> 
>> Keep in mind that these wire harnesses, like the car as a whole, was
>> designed to a budget.  These harnesses had three (count 'em, 3) fuses.  As
>> such some items were unfused like the headlamps and the coil.  And those
>> things that are fused shared a fuse so the fuse had to be sized to carry
>> the current for everything on that circuit.  But the wires were sized for
>> the particular load.  A thinner wire will have a nigher resistance and
>> under  short-circuit conditions the current can be limited to a level that
>> will not blow the fuse but the current will cause enough heating to cause
>> the insulation to melt.
>>
>> Another factor against us is the age of the harness.  The connector
>> contacts get corroded and will get hot under normal circumstances.  Wire
>> strands can fatigue and break within the insulation again resulting in
>> overheating under normal use.  The insulation gets stiff and cracks
>> exposing the wires within.  Lots of potential failure modes here.
>>
>> Compare this design to those found in modern cars you will see dozens of
>> fuses.  Sure there are a lot more electrical items but most things have
>> their own fuses.  This means you can size the fuse more appropriately for
>> the wire used to power that device.  Also the connectors used are water
>> tight and don't corrode as quickly.  Also, they are, on the whole, a lot
>> younger and therefore retain more of their original integrety.
>>
>> But a fresh works well enough so if you fear a melt-down a new harness
>> may be a good investment.
>>
>> Dave
>>
>>
>>
>> -----Original Message-----
>> From: bill beecher <notakitcar at yahoo.com>
>> To: Tom Householder <trhouse at columbus.rr.com>
>> Cc: Triumphs at Autox.team.net daily digest <triumphs at autox.team.net>; FOT
>> List <fot at autox.team.net>
>> Sent: Tue, Jun 23, 2020 8:52 am
>> Subject: Re: [TR] TR2-3 electrical melt downs
>>
>> Have a friend with a TR6 that had a significant meltdown behind the
>> dash.  I should think, given the right set of weaknesses, most any section
>> could melt.
>> Bill B
>>
>> Serenity Now......
>>
>> On Jun 23, 2020, at 4:52 AM, Tom Householder <trhouse at columbus.rr.com>
>> wrote:
>>
>> Over the years I have experienced and seen harness melt down in the
>> looms to the tail lights .. anyone ever had an under dash melt down?
>>
>> Trying to answer a question asked of me.
>>
>> Tom
>> ** triumphs at autox.team.net **
>>
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/pipermail/triumphs
>> http://www.team.net/archive
>>
>> Unsubscribe/Manage:
>> http://autox.team.net/mailman/options/triumphs/notakitcar@yahoo.com
>>
>>
>> ** triumphs at autox.team.net **
>>
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/pipermail/triumphs
>> http://www.team.net/archive
>>
>> Unsubscribe/Manage:
>> http://autox.team.net/mailman/options/triumphs/dave1massey@cs.com
>>
>> ** triumphs at autox.team.net **
>>
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/pipermail/triumphs
>> http://www.team.net/archive
>>
>> Unsubscribe/Manage:
>> http://autox.team.net/mailman/options/triumphs/john.macartney@ukpips.org.uk
>>
>> ** triumphs at autox.team.net **
>>
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/pipermail/triumphs
>> http://www.team.net/archive
>>
>> Unsubscribe/Manage:
>> http://autox.team.net/mailman/options/triumphs/don.hiscock@gmail.com
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/triumphs/attachments/20200624/fb34a956/attachment.htm>