9 replies to this topic

[Mrpeanut]

If I had a quid for every time I've heard the above phrase I'd be rich!.

I've spent hours scratching my head over mine and am still confused.

I have a mainstream 1991 carb cooper.

Somerford mini says it needs a gcl132 12v ballast coil, minispares say a gcl143 (a Lucas dlb198) which they say is a 12v ballast coil (although others describe that coil as a non ballast 12v electronic coil) and others say use any 12v non ballast coil such as a dlb105.

Other than the above, the advice is consistent!

My car has no pink/white wire so on the face of it no ballast, probably. Research suggests that the car does have a ballast within the loom though. See http://forum.minicoo...hp/t-12874.html

My car recently died suddenly at junctions and only restarted when cooled. My trusted mechanic suggested coil failure. That coil was an almost new gcl143. Assuming that coil had died I made enquiries as above.

I fitted a gcl132. Starting improved as if a ballast was boosting the starting. I also tried a dlb105 which got very hot so is now off

I now have 3 coils!

Questions.

1. Does anyone have a definitive answer as to whether this car has a ballast resistor system?
2. If in doubt what do I use?
3. What is a gcl143 coil, is it ballast or not?
4. What's the difference between a 12v coil and a 12v electronic coil? Does the latter have a volt boost like a ballast coil?

I'm probably being pedantic but given the confusing information I'm hoping you folks can enlighten be.

[icklemini]

1. Does anyone have a definitive answer as to whether this car has a ballast resistor system?
You got points? - or the electronic distributor?

3. What is a gcl143 coil, is it ballast or not?
Its for the electronic ignitions....

4. What's the difference between a 12v coil and a 12v electronic coil? Does the latter have a volt boost like a ballast coil?
The electronic coils have a lower resistence...

[Mrpeanut]

Its electronic ignition.

The resistance point I understand but it adds to the confusion! Some advice I've seen is to run a 3 ohm coil, others a 1 5.

The general view is that all minis from 1985 had a ballast in the loom, but seemingly the rsp, carb cooper and British open may not have.

[Ethel]

Any points system has around 3ohms resistance total in the LT circuit, the electronic systems aren't that far off either.

You can measure any ballast resistance: find the wire that's live on the coil +ve with the ignition on (usually white or white/pink striped), it'll spark if earthed against the engine block. Now, with the ignition turned off connect one end of an ohmmeter to that live wire, still detached from the +ve terminal on the coil. Touch the other side of the ohmmeter on a white wire at the fuse box - very little resistance = unballasted (including electronic). If it's ballasted the resistance should be around 1.5 ohms.

Note the ballast actually reduces the power in the system. That's because cranking the engine on the starter motor does the same. By using a lower resistance coil that works well when cranking, and using an equivalent ballasted supply when it isn't, you get consistent quality sparks without melting the ignition system when all the battery power is available. It's the wire to the coil, bypassing the ballast, that's key to a ballasted system - if you don't have one of them it's not ballasted ignition, or at least not one which works as it should.

Lucas electronic distributor modules have an internal resistance, hence you need a coil (GCL143) with a, lower, complimentary resistance.

Too much resistance drops the voltage and gives poor sparks, too little overheats the system and melts stuff.

[icklemini]

points = 3ohms coil resistence
points with ballast = 1.5ohms coil resistence
electronic / spi = 0.8ohms coil resistence

as ethel said: check the coild supply for resistence - ballast = 1.5 ohms, everything else needs 0...

[Shifty]

Surely the mainstream cooper will have the electronic dizzy?

(black module on the side)?

And yes coils do fail, but its also worth checking the module on the side of the dizzy, they can fail and/or have corroded terminals.

[Ethel]

Fridges last for decades because their moving parts are hermetically sealed inside the cooling system, Coils are also sealed & don't have any moving parts, if they don't last as long as your fridge it's nearly always because they have been abused by being fitted to the wrong system. - or perhaps fried by leaving the ignition on for hours without the engine running.

[Mrpeanut]

Cheers all.

This does have electronic ignition and I'll check the readings tomorrow.

Where I'm confused though is the readings. This is electronic and according to some has a ballast, and others it doesn't.

What ohm reading applies to electronic ignition if ballast fitted?

If its non ballast what damage would a non electronic (ie normal 12v )do? Could a 12v ballast coil be used without causing problems? On the latter point I recall a Calver article suggesting such a setup increased performance.

[Ethel]

Suppose it depends what people mean by ballasted - the concept predates electronic ignition and involves fitting additional resistance in series with the coil, as I attempted to explain above. Lucas's electronic modules also add resistance, but there's no starter bypass, so I wouldn't consider it ballasted - just a higher resistance system using a lower resistance coil. Fortunately electronic coils have the least resistance so fitting a wrong coil will be just like having a flat battery (low voltage) and shouldn't do any harm.

Who knows, maybe they made 'em like that on purpose?

[Mrpeanut]

Um, so if I get 1.5 ohm or 0 ... It makes no difference?

A 12v ballast type coil running at 1.5 ohm won't do harm?

The gcl143 (12v coil for electronic system) didn't start at all well, wheras the ballast type coil starts fine but runs at 1.5 ohm although the electronic system should have 0.something!

I'll test it on the meter tomorrow. I'll also test the volts going into the coil to see what they show and report back.

If anyone needs a coil I now have a selection going spare!