Ignition coil missing wires ?

[Garry]

Hello all.

Has anyone a photo/diagram (that a layman can understand) of Spit. Mk3 coil as I am not sure if mine has a wire  missing.

I have a pencil thick wire that heads off from the lower left hand spade connector towards the bulk head/battery  and another from the right hand spade connector which is connected to the distributor/points.

Should there be a third wire going somewhere else, if so, where?

Many thanks

Garry

 

 

[Eddie]

Does your car have a rev-counter, and if so is it working?

[KevinR]

MK3 spit should have a mechanical rev counter driven off the distributor.

 

I think that the MK3 Spit pre-dated the 6V coil and ballast resistor arrangement, in which case there should be four connections to the coil.

 

1.  The coil body itself should be grounded.

2.  The thick HT wire from the centre of the coil should go to the centre of the distributor cap.

3.  A thin wire should go from one of the spade terminals on the coil to the points in the distributor.

4.  A thin wire should go from the spade terminals on the other side of the coil to an ignition switched 12V line (at the ignition switch)

 

The MKIV Spitfire had an extra wire going to the coil to implement the 6V ballasted coil arrangement.

Wire (4) above had a 1.5 ohm resistor in it (on the MKIV Spit it was a discrete resistor sat beside the coil, on the 1500 Spit it was a length of wire going back to the ignition switch and it was a resistive wire. 

The extra wire went from the same coil terminal to an auxiliary contact on the solenoid, so that a full 12V was applied to the coil during cranking, but once the engine was running, the coil got 6V and 6V was lost across the ballast resistor.

[Garry]

Hello.

Eddie and KevinR thanks for your replies, I really appreciate them.

The car does have a rev counter but I haven't checked if it is working. I will check it tomorrow and update then. What does it mean if it is not working.

I definitely have two of the connections listed above. Number 2 and number 3 are there. I am not sure about Numbers1 and 4.

When I tried to start the car last week the engine would turn but not start until the battery went flat. I have recharged the battery and the car starts first time.

If connection 4 as listed above was missing would the car start?

[KevinR]

Garry,

 

Connection number 1 is having the coil screwed down properly - it wont work if its not screwed down.

 

Connection 4 is required to make the car start, but you can "hot wire" the car by connecting a wire direct from the terminal on the coil to the +ve of the battery and bypass the ignition switch - this is what the thieving scroates used to do (still do if they are old enough to know how)

[Garry]

KevinR

The car started today without hot wiring so I am assuming that connections 1 and 4 are there. I can definitely see connections 2 and 3. Maybe I am wrong in thinking there is a wire missing (effects of old age)!

The Mk 3 does predate the 6 volt coil.

Thanks for your advice.

Garry

[Eddie]

The car does have a rev counter but I haven't checked if it is working. I will check it tomorrow and update then.

 

I was thinking that the missing 3rd wire might be for a rev counter, but if the car has a mechanical rev counter as KevinR says then you can ignore that.

[thescrapman]

A Mk3 spitfire may have a feed from the coil to power the overdrive loom.

 

Other Triumph models certainly do get the feed from there, so a Spitfire may be the same.

 

Cheers

 

Colin