A final update and a thank you for all the help proferred.
The relay was kaput.
The throttle switch points are closed whilst the accelerator is from
disengaged to, say, 20% engaged. Given a dead relay, juice will get to the
solenoid
via the throttle switch until the accelerator is depressed by, say, 21%
whereupon the throttle switch's points open and the solenoid drops out as it
no
longer gets any power.
Bridging the overdrive switch and having the system work seemed, at first
glance, to point to the throttle switch being at fault but actually it - given
the peculiar symtoms - confirmed the diagnosis.
My thanks to all and sundry. The diagram that I received and an article from
a magazine were particularly helpful. And someone owes me a Guinness?
A friend said that the Healey overdrive system has more points and bypasses
than the London Underground! It certainly is an utter dog's breakfast.
Simon.
|