Welcome to the Irish Mini Owners Club forum. Celebrating 30 years of the Irish Mini Owners Club, 60 years of the Mini, 50 years of the Clubman and 20 years of our flagship event MTM
The mini broke down last nite in clontarf, couldnt get a spark so had to get it towed. From what i can see with my multimeter is that the coil is bunched, i get 12v into the positive so im getting power.
The resistanc across the LT side is o.01 Ohms and I cant even get a reading between the + and the HT side.
The Power line in gets very hot when the ignition is on, but doesnt when disconnected from coil, so I think there is a short in the coil.
Does anybody agree with this? or could the electronic module in the dizzy be the fault? The fault is certainly between the coil and the electronic module.
Thanks
The resistance across the LT terminals should be up around 3 ohms for a standard coil and just under 1.5 ohms for the electronic ignition one, and the HT should be up in the thousands.
Try this test....Take off the HT lead from coil to distributor and replace it with one of the plug leads (leave the plug connected to the lead). Use a vice-grip to clamp the plug to the nut that holds the coil clamp to the head. Disconnect the negative wire from the coil. Get a piece of wire and attach one end to the negative terminal on the coil.
Turn on the ignition then touch this wire to earth and take it away again. Do this quickly a few times and the plug should spark (as well as the wire you are touching to earth).
no spark means your coil is knackered.
Sorry for the long-winded explanation, I just wanted to make sure you knew what I meant.
If you do have to replace your coil try to get the specific electronic ignition one. the standard points one will work but wont last as long....something about electronic ignition being harder on coils because it switches faster than points.
Last edited by mgb1978 on Thu Jul 01, 2010 3:54 pm, edited 1 time in total.
LOng winded in good! Thanks mate, ill do that after work and see, would that test point to the electronic module too as all that does is earth the coild for the spark?
If you try that test you will only be testing the coil. You will have isolated the coil from the ignition so you should at least know if it's the coil or the electronic ignition that's giving trouble.
My money would be on the coil...the electronic ignition rarely gives trouble.
Just a quick question about ballast and non-ballast coils. Mine is a 91, so from reading up, I would actually ned a ballast coil and not a non-ballast.
But correct me if im wrong, but I should only be getting 9v at the +ve on the coil as the ballast resistor will drop 3v?
Where as a non ballast would need the 12v?
Im getting 12V at my +ve side so does this mean i need to drop the 3V?
Now is the ballast resistor a actual resistor or just the cable has a high resistance to drop the voltage?
Last edited by kona on Fri Jul 02, 2010 1:48 pm, edited 1 time in total.
If you have a ballast system there should be two seperate wires feeding the + terminal on your coil.
The pink wire will be the resistive wire (no seperate resistor) and the 12v feed (for starting) should be white.
By the way if it is a '91 car with electronic ignition then it is a Cooper, Right ?
The voltage reading at the ballest coil can be misleading and complicated and is best measured with the engine running.
Without the engine running the points system will give a reading of 0 when points are open and 12v when points are closed, electronic systems can give different readings .
woody wrote:The voltage reading at the ballest coil can be misleading and complicated and is best measured with the engine running..
I measured it at the cable, when it was disconnected from the coil.
woody wrote:Without the engine running the points system will give a reading of 0 when points are open and 12v when points are closed, electronic systems can give different readings .
