List, Rare MGB problem. On 75/76 MGBs there are diodes on the right side
footwell panel. They regulate current from the starter/parking brake light
switch.If a diode fails when you put the parking brake on the starter can
engage even though the ignition is off. Weird problem that occurred on my 76B.
I read the tech description on the Sacremento MG Car Club web page. For your
info. Cut off switch a good idea if you remember to use it all the time.Doug
From: Bob Howard
Sent: Sunday, February 06, 2000 7:23 AM
Subject: Re: Battery Size info / battery cutoff switch
I am a believer in the cut off switch too, having one in my TD and one
in my MGB-GT. Not only for the reduction in the chance of electrical
misfortune, but simply for the convienience, are they great.
A week ago Friday, I got a call from a club member whose '76 is her
daily driver. She took it from work to get lunch for the staff, returned
to the office and parked it. Later, some of the staff were laughing about
her parking her B in a snowbank. Seems that she left the car in gear,
starter chose to engage, and powered the car across a parking lot, up a
curbing, and into the bank where it stopped and the starter turned the
drivetrain until battery and starter died.
They still haven't figured out exactly why this happened. As I
understand it, the wires running up from solenoid to relay and to the
distribution junction were both fried. Who knows--could have been
ice/snow abrasion or build up, something run over on the road--just no
real way to tell.
However, had a $25 switch been in the car, this could not have happened
to an unattended vehicle, and a minor problem could have been much more
On Sat, 05 Feb 2000 11:53:22 +0000 Dave Houser <firstname.lastname@example.org>
> With all this talk about batteries and box sizes, I hope everyone
> replacing their batteries also installs a battery cut-off switch
> too! For safety's sake, it's a lot easier to throw a switch than
> to unscrew those five dzus fasteners or watch the flames go ever
> I put em on all my MGs and I'm resting a little easier.
> Dave Houser