Help, wiring gurus needed

[Kent McLean]

Huw Powell wrote:
>> So, my question is, if they did not disconnect the older shorted wire
>> from the license plate lamp, would it have caused the short to blow
>> up the IC?
> 
> ... Why didn't they just find the short and fix it?

My opinion:  if they didn't disconnect the original shorted
wire, then the new wire from the tail light to the license
plate light fed 12 V back along the shorted wire.  Since
there was no fuse to protect the shorted wire (the fuse being
on the other side of the short), it smoked the wiring.

The original plan *may* have worked if they a) disconnected
the shorted wire and b) did the math to make sure that adding
the license plate light (lights?) didn't overload the existing
wiring to the tail light. That is, wiring that might have been
designed for a 7 watt bulb now has to provide power for three
7 watt bulbs, or 3 times what the circuit was designed for.

That's what I think, and I agree with Huw -- why didn't they
fix the short?  They can argue that it might have taken an
hour or two of labor to find the short, and their fix would
save some time.  But now you have an hour or two of labor to
repair the damage, you still have a circuit drawing more
power than it was designed for, and the short still hasn't
been fixed. Three strikes, you're out. (Sorry, it's baseball
season.)

Find a better shop, and maybe a lawyer.

--
Kent McLean
'94 100 S Avant, "Moody"
'89 200 TQ, "Bad Puppy" up in smoke
'56 Austin-Healey 100 BN2, for sale