misc to robert & list

[rdh@sli.com (Robert D. Houk)]

   Crimp connections, if done correctly ( by machine ) are just as good as
   solder connections. At our factory we have from time to time investigated
   their performance, and they are very reliable, and have almost no voltage
   drop.
   Try and take a good crimped joint and cut it off in the middle of the
   crimp, and you will see what I mean. It looks like solid copped all 
   through.

I agree that a good "factory" (automated high-power machine) crimp is
an excellant electrical and mechanical connection. For several years.
At least 5 if done well. (I believe -- but am not sure about this par-
ticular tidbit -- that a *strong* machine crimp will actually result in
a contact/surface welding of the components, which is electrically as
good as a solder joint can be...)

But the problem with crimped connectors, especially ones exposed to
the corrosive environments found in engine compartments (and around
headlights) is that over time the crimp can loosen slightly, and/or
suffer corrosion damage to the surface contacts, resulting in a lousy
connection. This happens to all cars alike, without apparent regard
to race, creed, color, nationality, etc. and so forth. Once the effect
starts, it snowballs, and soon you have a serious problem. Soldering
the wire to the connector tends to "seal" the connection against
encroaching corrosion and ensures a good electrical (and mechanical)
joint.

It is even worse with the interface 'twixt connectors, as they don't have
nearly the mechanical seal of the actual crimp itself from wire to con-
nector. (But they at least offer the dubious distinction of being some-
what self-cleaning: unplugging and replugging the connector "cleans" the
surface oxidation/corrosion and restores a good electrical connection for
awhile again...) Gold [plated] connectors are wonderful, as they do not
corrode (why do you think computers use them all the time for PC-board
connections!), but probably adds a penny or two the price of *each* con-
nector. So they are not (in general) used. Silver is an even better con-
ductor (and a hell of a lot cheaper too!), but oxidizes "instantly" on
exposure to air, so is restricted to "sealed switch" innards (and over-
priced GoldenEars Audio cables).

The problem is only exacerbated by Audi's underspec'ing the wiring in the
first place, resulting in the wire itself running hot (not "warm", "hot").

					-RDH