Classic cars forum & vehicle restoration.

[TTotal]

While I am waiting to sort my windscreen headache, I am wondering about my little occasional starting oddity.

Recently when starting up my Velox 1600 petrol powered 1965 Bedford CA , it instantly cuts out - unless I hold the key in the start position which off course keeps the starter engaged.After about 2 seconds of this the engine runs fine.

My friendly old style mechanic says that my CA has a 7 volt coil which when it starts off changes to 12 volt and that there is a resistor in the circuit...

Why? What for? Can we remove this and install a "normal" system?

Cheers all.

John
_________________

[ukdave2002]

Hi TTotal

You can change to a normal 12V coil and remove the ballast resistor, but you then loose the benifits of better starting.
When starting the starter motor suppy it also attached directly to the coil, so when you start you are applying 12v to normally a 6v coil and benifit from a better spark,(at a time when the battery voltage probably drops to about 10V) when you realease the starter the supply is cut from the coil and it is supplied 12 v via the resistor.

Its a good system that really is only not used these days since the introduction of electronic systems.

Dave

[peter scott]

Hi TT,

When the starter motor is running the battery voltage drops considerably. This is especially true in cold weather and so the ignition system generates a proportionally weaker spark whilst the starter is running.

The 7 volt coil is a very good device for improving cold starting. If your CA only runs when the starter motor is running then it suggests that the coil is working correctly but the resistor has gone open circuit.

I think some manufacturers used a resistive cable instead of an actual resistor component so don't be surprised if you can't find the component.
My advice would be to retain the 7 volt coil and fix the resistor.

Peter

edit: Dave beat me to it.
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[TTotal]

Peter , feel so humble seeing your selection of Tube videos! Superb SS you must be proud.
Thanks for the advice.

John
_________________

[peter scott]

Hi John,

Thanks for your kind words. The SS stuff must seem like a bit of an obession, well, I suppose it is, but I am interested in other old vehicles too.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[Penman]

Hi
The HB or HC Viva used a ballast resistor low voltage coil system.
I wonder if was a Vauxhall thing and was used for all/most models.

[Phil - Nottingham]

Standard ballast system - Holdens sell new ones and not expensive
_________________
Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2

[TTotal]

[peter scott]

http://www.holden.co.uk/
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[TTotal]

Interesting stuff there, specially the Lumenition, may consider that ignition system rather than points/condenser etc ...

Thanks again !

John
_________________