In a triumph of deductive logic, I found the problem. Some additional
facts I should have given:
1) I put in a cigarette lighter at the weekend, involving connections
to the fuse block after considering the accessories position on
the ignition switch.
2) I had the speedo binnacle out while doing 1)
after 1) and 2)
3) The ammeter was doing funny things, ie not showing much movement
either way when driving, braking, lights on etc.
3) led me to believe that I had done something wrong in 1) or there
was something wrong with the regulator &/or generator. In fact the
night before I checked the regulator to see it was working correctly.
When I got back to the car last night, I tried to no avail. I was on
a bit of a slope so tried clutch starting it by popping the clutch
while rolling in 1st gear. It gave a slight cough, but that was it.
Using the little rechargeable torch that lives in the cigarette lighter
(the whole reason for installing it in the first place) I checked out
the carby for flooding (Nup), loose wires etc. Nothing obvious.
Disconnected the tacho from across the coil in case it was doing something
funny. Flicked the points to see that power was reaching them, Yep.
Diconnected the plug lead to No. 1 cylinder and cranked it over. (Good
thing about these old cars, you can reach the starter solenoid easily!
A feeble excuse for a spark just managed to leap across a 1cm gap. Hmmm.
Inspiration! hot wire the coil direct from the battery. Luckily had
wire and pliers in the car from 1). Started straight away!!
At home I then started doing some measuring. Battery terminal voltage
12.5V. Coil voltage 10!! Pulled the HT lead, cranking voltage 9!
With such a voltage drop to the coil there was something amiss.
Check resistances through various sections while consulting the wiring
diagram. 5 ohm between battery and coil. Where does the fat yellow wire
go to from the starter solenoid (Battery end)? Branches to Yellow/Black
which goes to the ammeter.
Pull out the speedo binnacle (well get it out far enough to swivel it around
then while laying half on the seat and half on the floor, examine the
ammeter). Sure enough the connection was very loose.
After tightening it up, the coil voltage was 12V which made a huge difference
to the starting, now as good as it ever was.
In all my years of motoring and LBC ownership Ive never struck this before
(although I nearly set fire to my Mini when the leads at the back of the
ammeter shorted and welded themselves together!)
Anyway, hope this has been instructive for those who might
find themselves in this situation in future.
paulr
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