Here is how to carry out a few basic tests on your Ignition Coil
One of the first things to check around any coil is that it must be kept clean from any dirt/oil/moisture to prevent the HT Spark from tracking to earth as it will always look for the shortest path to ground, this may well be on a dirty coil straight out the turret and track to the nearest earthing point. So its important to wipe the coil off around the LT (Low Tension) connections (+ & - Connections) and keep them oil free and dry.
If you see any signs of oil running out from the canister then you need a new coil straight away.
If your Coil is unduly hot then follow the information here http://www.theminifo...checks-answers/ and do the checks to see if your coil is running to hot.
Testing the coil
For preliminary test, use an ohm meter to check the resistance of the windings of the coil.
Non Ballasted Coils
For a non-ballasted ignition system like the pre-1984 Cars, coil primary resistance should be about 3.5 ohms between the + & - terminals (see Primary testing picture below).
A high energy coil may have slightly lower primary resistance of 3 -3.2 ohms.
Ballasted Coils
A coil for use with a ballasted type ignition system (84-on ) will have about half as much primary resistance, around 1.5 ohms and is tested in exactly the same way.
O.E Electronic Ignitions
These use a special coil on cars with the 65DM4 Distributor, and have a primary resistance of 0.89-1 ohms and is also tested in exactly the same way as the Non Ballasted and the Ballasted. It is important however to ensure the correct coil is fitted to the system as a incorrect model of coil with the wrong primary resistance will cause the electronic module to fail.
Resistance for the secondary winding will be very high, something like 7,500 to 10,000 ohms. Check that circuit resistance between the HT output and one of the primary input terminals.
Connect the king lead to a spark plug and hold the plug against the cylinder head and crank the car over and you should see a spark across the plug. You may wish to hold this with insulated pliers to avoid a shock.
How Do I Know Which Coil I Have?
Standard coils have 1 white wire to the Coil Positive and show 12v+ on that terminal
Ballasted Coils have a white/pink wire of 9v and a white/yellow of 12v+ fed from the starter solenoid upon starting
O.E Electronic coils have a 12v feed to the Coil Positive and 2 wires going onto the module on the outside of the distributor body.
Types of Coils and part numbers
Standard Ignition 12v DLB101
Original mini coil GCL216 fitted to all cars up to the introduction of the ballast type in 1984 3.5 ohmn
BALLAST IGNITION 83-ON DLB102
Ballast type coil fitted from 1984 up until 1989 998cc cars,
GCL143 was original equipment and GCL217 was the aftermarket replacement 1.5ohmn
O.E Electronic Ignition 89-on DLB198
This is the standard coil as used on the late Mini with factory electronic ignition. This was a Genuine Rover fitted part on 1275cc. GCL211 is the same equivalent as GCL143 but from Unipart. 1 ohmn
Lucas Sports Coil
DLB 105 Suits all 12v systems with points or aftermarket electronic modules 3.5 ohms
Sports Type 12v Coils
MSC105 3.5 ohms
Attached Files
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Coil Test.png 19.29K
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