ignition coil of morris minor 1000 car-1957 -is heating

[Sandun]

Ignition coil of Morris minor 1000 - 1957 year- is very Hot and Stop the car ( Not Normal) when I drive 10 km - tell me why ?
I did
1. Changed the Condenser
2.Checked coil ( Lucas old Coil)
3.Changed Sparking plugs
4.Checked Point gap
5.Checked + ,- wires all are Fine
But Still coil Hot

[Alec]

Hello Sandun,

there is some confusion as there are generally two types of coil, a standard 12v which should be fitted to the Minor and a ballast type coil which is used on some vehicles. Unfortunately they are sometimes also marked 12v.
The ballast type coil runs with about 8 volts so if you fit one to a Minor it will run hot.

If you measure the primary winding resistance (+ ve terminal to - ve terminal) with a meter, and it is less than 2 ohms you have the wrong coil, the correct one has about 3 ohms.

Alec

[Sandun]

I measured the primary winding resistance ,it is fine - I have Lucas Old 12v coil - Morris minor 1000 -1957 year[frame][/frame]

[bmcecosse]

I've asked this before - 'it's fine' doesn't tell us anything useful..........we need to know what the OHMS reading is between the two small terminals. It should be 3.2 ohms - if it's any less then yes it will overheat, and quite quickly burn out.... Coils do get 'warm' in use - can you measure the surface temperature in any way ? Is it so hot that you can't hold your hand on it ??

[Ratbag]

If it used to be OK then its probably not the coil.
there are some bad 'new' condensers out there that give this symptom.

Phil.