What Coil for 1970 HB

[Crystalvoyager]

Hi there, can anyone tell me what coil I need to get for my 1970 1159cc viva hb.
I don't know how to tell if the coil fitted at the moment is a ballast or non ballast coil other than there are only two wires attached to it.
the chaps at my local auto electricans tell me it should be a ballast resistor type coil.
thanks in advance

[1972nail]

You need an Accuspark Blue coil. It's suitable for the 'ballast wire' type ignition circuit in Vivas.

[Crystalvoyager]

That's great, thanks for that I'll look into getting one.

[Crystalvoyager]

Do I need to wire a resistor in with the blue coil or do I just fit the unit on its own and attach the two wires?
Cheerz in advance

[1972nail]

There is a resistasnce wire built into the loom of the HC but I'm not sure about the HB.

A ballast resistor coil is designed to run on a reduced voltage, usually about 9V. Quite simply, the resistor normally in circuit is bypassed during cranking the starter which gives a full 12V to the coil and a fatter cold start spark. Once running and the key is released the resistor is brought back into circuit so that the coil gets its designed voltage. If you run a resistor coil at 12V constantly it will prematurely fail as it is being over driven.

To check if a resistor is already fitted to the car is a quite simple operation. First of all check the battery voltage, it should be 12 to 13V without the engine running, anything less and it needs charged. Next, with a fully charged battery, switch the ignition on without starting the car, i.e. the red light on the dash is on. Check the voltage at the coil, if it is between 8 to 10V then there is a resistor in circuit, if it is 12 to 13V, the same as the battery, there is no resistor in circuit.

[Crystalvoyager]

Oh I see that makes it a bit clearer . I would of thought someone on here who owns a hb would of been kind enough to help. I guess I'll be able to tell from the wiring diagram whether it's got an inbuilt ballast wire. I've got a manual on its way from eBay. Many thanks for your help.

[Dormobile Roma]

If it has a resister coil it needs two power supplies to the coil, one from the ignition and an extra one from the starter solenoid. The wiring diagrams I have for the HB show that there is a small unit called an 'Ignition Coil Resister' which as three wires connected to it before the coil. Two wires are just white (including the one to the coil itself) but the third is white and blue. I have a HA so mine is different but on the Bedford CF I had the 'Ignition Coil Resister' was actually a small unit about an inch long mounted on the connection on the coil.

There is also a wire from the coil to the distributor that will be white and black (or green if it is Bosch distributor).

Hope this helps.

Martin

[Crystalvoyager]

Hi Martin.
Thanks for the advice, now that I've got the car home I can inspect it properly.
There isn't a resistor fitted but there is a little blue plastic unit attached to the rocker cover right next to the coil. This little unit only has I wire coming out of it and isn't connected to anything. I thought it might be a suppressor as I found another one of the little blue things attached to the back of the alternator too. But the vehicle doesn't have a radio so I've no idea what on earth they are. There is only one wire coming out of the loom to the coil and one wire from the coil to the dizzy it looks like the blue thing has as one time been attached to one of the coil wires by way of a scotch lock. With the ignition on there is a live feed to the dizzy but no spark when I open the points.

[1972nail]

The blue things are suppressors. The car may have had a radio in the past or the ignition may have been so 'noisy' that it was affecting neighbour's tv's!

[Crystalvoyager]

Oh I see, thanks for the advice.
I've got my manual thru now and I see on the wiring diagrams that my model is the 'alternator (lucas ACR & coil feed resistance).
However get this - on the wiring diagrams it shows several wires leading to the back of the alternator whereas on my car there is only two wires. One heavy and one normal size wire.