Hi Rick,
As you decribed there was a clear indication a physical damaged wiring loom
part. Propably the spare tyre chafed the wires connecting to the bottom of
the trunk.
I therefore would like to opt for your approach run the loom where all
damages are and have the involved wires replaced. Have the loom better
secured out of reach of the spare tyre in the future. Although have the
spare tyre better secured so it can't move anymore. There is a special thin
for locking the spare tyre into the boot.
I recommend to use the appropiate colors here, because later troobleshooting
almost will be impossible or drive you crazy.
The red wire is the live for the licenceplate lamps, red rear lights and if
applicable the red side lights (USA only).
Using a decent electrical schematic surely will help here, although not an
absolute neccaty. (As a computer engineer I repaired a wire wrap backpanel
of a complex disk drive where one wire had been hot and so damaging about 25
other wires' insulation without using a manual nore knowing the drive @ all)
Cheers,
Hans
-----Original Message-----
From: Rick Huber [mailto:rickhuber1@home.com]
Sent: maandag 19 juni 2000 12:54
To: mgs@autox.team.net; Andrew Huber
Subject: Prince of Darkness strikes Brake Lights
Hi All,
When the policeman stopped behind me and hollered that my brake lights in my
75 MGB weren't working, I thought, yea, one of those connectors has come
loose in the trunk again, no problem. Boy was I surprised !
When I started digging in the boot, I found about one foot of burnt / melted
wires between the spare tire covering carpet and the back wall of the boot.
It's the harness between where the ground wires come out on the right hand
side and where the wires to the left hand license plate light come out of
the harness. It looks like the worst burned/melted wire is the red wire
that supplies power across the back of the boot, but I'm thinking that
another wire shorted it and caused the extra heat. The worst is around the
harness where the license plate light take off is, where a red wire loop and
a connector are located. The connector is melted as is the insulation cover
over the red wire supplying power to the license plate light. Four or five
other wires are also burned through and the metal wires are exposed,
including the green with purple stripe wire that powers the brake lights.
I'm lucky it didn't start a fire with the boot carpet.
The funny thing is that all the other rear lights continue to work - back
up, running lights, license plate lights, turn signals - only the brake
lights don't work.
First time in 23 years driving MG's to have a wiring harness burn up - I
guess I was due. So now I guess the thing to do is to unravel the burned /
melted mess, replace each wire one by one, and then try it all again. I'm a
bit leary about putting power back through the system without identifying
the cause of the short. Is it foolish to believe that two wires have chafed
and shorted together, or should I look hard to make sure there's not still a
short that will cause the new wires to do the same thing ?
Safety Fast,
Rick Huber
75 V8 MGB
65 MGB undergoing lengthy restoration
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