Barney:
I feel that there is enough false info floating around about our
LBC's I had to put a word in. I have never seen an instance of an
identical Lucas part having two part numbers for different applications.
If you have an example, please give me the part numbers. I am
comfortable being proved wrong.
The vehicle manufacturer specifies the operating characteristics
of the components. If the component manufacturer does not have a
suitable part in production, then a new part number is created. Many
times the components are externally similar. The change may be a subtle
difference in rating, connection or tolerance. Over the time of
production, these specifications may change as operating problems
develop. Each time there is a change in specification, a new part
number is developed. This prevents superceded parts from being
installed in warranty vehicles. As time goes by these multiple designs
become rationalized to a current production number which will perform
the task. Stocks of the superceded parts are still out there, they do
not disapear. Many times they show up at swap meets. Some of the parts
may meet the demands of service, many will not. For best reliability,
the correct, latest recomended part number is going to be the best bet.
It may not look like what came in the car, but it will meet the original
operating specifications.
Every time a number is created, stock levels are increased and
inventory costs climb. No manufacturer is going to purposely increase
inventory costs, in an attempt to increase revenue.
In the case of this relay, the model number identifies the case design
family. Within a relay case design family there may be many different
functions. S.P.S.T., S.P.D.T., latching, momentary, single terminal
out, dual terminal out, etc. Obviously if you only need a single
terminal out, a relay with correct characteristics (or heavier) with
dual terminal out can be used. Vice versa if you are willing to use a
two to one adapter connector.
Another example. MGBs' and Midgets from 68-76 all use the same
model number turn signal switch (119SA). The different part numbers
relate to changes in; legend, horn function, finish on horn button, plug
design, angle or length of stalk. The switches all look similar, they
will mechanically interchange. The design changes were dictated by
changes in legal standards (mostly federal), steering wheel design,
connector supply, customer/market input.
These changes cost the manufacturer a fortune. The constantly
changing federal requirements ended up contributing to Leyland's pulling
out of the market.
I am not aware of any tricks being pulled on the public. The
auto industry is too sensitive to competition to allow conspiracies that
would hurt the profitability of the aftermarket repair industry. This
is evidenced by the non-duplication of part numbers within the
aftermarket supply industry. Quite the opposite, in many cases ill
conceived substitution can destroy the reliability of our cars.
Example. A major national supply chain is supplying under rated BMW
Jurid driveshaft couplings as heavier duty XJ6 units. They both look
alike. The BMW ones bolt in. The BMW ones are cheaper. The repair
shops wonder why their good customers come in with ripped out couplings
prematurely.
My apologies for the length of the post. But we all face these
questions and problems as we source parts for our cars.
Kelvin.
-----Original Message-----
From: Barney Gaylord [mailto:barneymg@ntsource.com]
Sent: Sunday, November 22, 1998 8:53 PM
To: larry.g.unger@lmco.com
Cc: fisher@hctc.net; mgs@autox.team.net
Subject: Re: MGA: Optional Headlamp Flasher Relay
At 09:05 PM 11/22/98 -0500, Unger, Larry G wrote:
>I've been searching for the relay (Lucas Model # SB40-1, Part # 33135B)
....
>
>However, I have found a NOS relay that is identical in appearance (same
model number), but it has a different part number (33157) and is
intended
for use in conjunction with the O/D on an Austin Healy 3000 ... its
rated
at 12v, but info regarding its amperage rating isn't on the relay or da
box. So, the question is ... if I fit the relay that is intended for
the
O/D will it handle the amperage for the headlamps? ... or, will I just
toast a NOS bit?
I realize that this is not a trick question, but the answer is a trick
on
the public by the car manufacturer (not the relay manufacturer). If it
bears the same Lucas model number, it is probably the same part. Quite
often the car manufactures specify different part numbers for the same
physical part when used on different models of cars. Among other
things,
that allowes them to use some creative pricing strategies, like doubling
or
tripling the retail price when it was shown in the parts list for cars
being more expensive or more exclusive.
It needs to handle about a 10 amp load, but only intermitently when used
for a headlamp flasher. When in doubt, hook it up to the headlights,
and
give it a try. If it works for 1 minute continuously it will likely be
fine for this purpose. If you want to give it a real test, turn it on,
let
it run for 20 minutes and see if it gets hot. It will probably work
okay,
because the OD is a continuous duty application.
Barney Gaylord
1958 MGA with an attitude
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