Hi Eric

There isn't a starter relay in your car. The floor switch does that job. The
small wire off the switch should be brown and goes to the 'A' terminal of
the regulator box. This terminal also provides the main feed to the fuse
box. So the suggestion is there is a fault with this wire. Has it melted on
the exhaust maybe? Or has the brown wire at the fuse box broken?

HTH

1.  You are on the right lines.  The smaller lead from the starter switch on
the floor goes off to the ign and other circuits, start checking for power
from here on.

2.  There is no starter relay, the button on the floor is a heavy duty
switch.

3.  You must just find the first point that is live then find where it is
stops being live !  Likely points are : at the connection under the starter
switch, at any joins, the ignition switch and especially its connections.

MrCheerful

Gawd, you're testing my memory now.
The starter switch is purely mechanical, ie: pushing the button down pushes
a fat piece of brass across the terminals of the positive lead.
Could possibly be the negative lead because for several years in the 1960's
no-one could make up their minds about polarity and they kept swapping the
earth around.
Pushing the button down and getting the starter to spin proves only that the
battery has a charge and the starter works. It doesn't indicate that the
coil is receiving any current.
At the limits of my memory now- the main fuse is under the bonnet hidden
behind the soundproof material by  the wiper motor. It's a line fuse in a
bullet type holder. When that fails you lose warning lights and power to the
petrol pump and ignition.
If that fuse is ok, suspect the ignition switch. To get you going, those
engines are the easiest in the world to hot wire- just run a lead from a
permanent live source to the low tension connection + on the coil.
DaveK.

IIRC, there is a fuse box with only two fuses, but these aren't used for
the ignition, etc. However, one *is* fed off the ignition switch as it
protects ignition controlled acessories (indicators, brake lights, heater
etc). The other is permanently live as it protects those accessories which
work with the ignition off, like horn, etc.

If there's no volts at the input to the 'ignition' fuse on this box with
the ignition on, my first guess would be a faulty ignition switch.

Again, IIRC, there's only a wire from the pickup point on the starter
switch to the ignition switch, so I'd also check that there are volts
arriving at the ignition switch at all times. If there's not, a dirty or
broken connection where the wire picks up from the starter switch would be
next.