24 replies to this topic

[Chelsea_Pete]

Hi chaps,

My minis been experiencing lumpy acceleration, misfires and a wild tacho since I got it back on the road after a couple of years.
After doing my homework it looks like this could be related to a dodgy coil, so I want to replace it.

When looking to see if it is a ballasted or non-ballast coil, I was confused to see the (infamous) Pink/White wire to the +, but no other, surely there should be 2?

The car & loom is from '86 (engine '90 metro A+), so I would assume Ballasted, but it has been messed about with a lot before I owned it!

Attached a photo, any advice on whether this system is ballast or non? (or whether its a bad bodge I need to sort out!)

Have cleaned and replaced terminals at the coil, new spark plugs and ht leads, and reset the contact points so the lumpy acceleration isnt that. 

Cheers, Pete

Attached Files

•  DSC_07551-min.JPG   29.7K   8 downloads

Edited by Chelsea_Pete, 06 August 2018 - 01:41 PM.

[unburntfuelinthemorning]

If it is ballasted then that's the wrong coil as it's a 12 volt one and ballasted systems use a 9 volt coil.

 

If you have a multimeter measure the voltage at the positive terminal on the coil with the ignition on.  A normal system will show around 12 volts but a ballasted system will show around 9 volts or thereabouts increasing to 12 volts when the starter motor is operated.

[GraemeC]

There should be two wires on a ballast coil - a white/yellow to provide the cranking bypass.

You could measure the resistance of the coil and ascertain if it is ballast or not, and then measure the voltage at its +ve terminal whilst running and see if it getting over 12V or nearer 9V.

 

If you're in any doubt, I would simply put a non-ballast coil in and run a new 12V ignition feed from the fuse box, then you know it is OK .

Edited by GraemeC, 06 August 2018 - 01:53 PM.

[Cooperman]

The 'effing pink and white' wire is a real pita. When it overheats and fails it takes a good portion of the front loom with it. The last time I had to repair this damage it took me over 6 hours and had to buy a load of correct colour cable.
Best thing is to cut the pink/white cable at each end and replace it with a white cable, then fit a 12 volt coil.
That removes the risk entirely.

Edited by Cooperman, 06 August 2018 - 02:00 PM.

[Chelsea_Pete]

If it is ballasted then that's the wrong coil as it's a 12 volt one and ballasted systems use a 9 volt coil.

 

If you have a multimeter measure the voltage at the positive terminal on the coil with the ignition on.  A normal system will show around 12 volts but a ballasted system will show around 9 volts or thereabouts increasing to 12 volts when the starter motor is operated.

Hi thanks for replying,

Multimeter is showing 6.5v with just the ignition, jumping to 10.3v after starting (cant check just the starter motor till an assistant shows up)

So perhaps I'm running on the wrong coil, but what confuses me is why there isn't 2 wires into the +ve as ballasted systems are supposed to have? And why the +ve feed is Pink/White, I would assume this needs changing as its the ballast wire, operating a non ballast system?

I should add that there arent any problems starting either. Maybe best to wire up a new 12v coil and replac that pink/white ballast wire?

 

Edited by Chelsea_Pete, 06 August 2018 - 03:01 PM.

[unburntfuelinthemorning]

There should be the white/pink wire which comes from the ballast resistor but also a white/yellow wire which comes from the starter solenoid and supplies full battery voltage when the starter is operated so the white/yellow wire is missing.

 

Turns out 6.5v is spot on with just the ignition on for a ballast resistor supply.

 

So you're running a 12 volt coil with less than 12 volts which won't help it to run well. 

 

You need to either find and fit the white/yellow wire and fit the correct type of coil for a ballast ignition system to retain the advantages of it which is that the coil receives more than enough voltage to ensure a good spark under all starting conditions (e.g. cold temperatures) or keep your 12 volt coil , ditch the white/pink wire and run an ignition live wire to the coil.  Apparently the white wire which is the ignition live wire for non-ballast ignition systems is retained in the wiring harness to accomodate vehicles with conventional ignition systems.  That'll save running a new wire and will keep things nice and neat if you can find it.

 

I've never had trouble starting a Mini with a conventional ignition system no matter how cold it's been so I'd ditch the ballast resistor.

Edited by unburntfuelinthemorning, 06 August 2018 - 04:29 PM.

[Chelsea_Pete]

There should be the white/pink wire which comes from the ballast resistor but also a white/yellow wire which comes from the starter solenoid and supplies full battery voltage when the starter is operated so the white/yellow wire is missing.

 

Turns out 6.5v is spot on with just the ignition on for a ballast resistor supply.

 

So you're running a 12 volt coil with less than 12 volts which won't help it to run well. 

 

You need to either find and fit the white/yellow wire and fit the correct type of coil for a ballast ignition system to retain the advantages of it which is that the coil receives more than enough voltage to ensure a good spark under all starting conditions (e.g. cold temperatures) or keep your 12 volt coil , ditch the white/pink wire and run an ignition live wire to the coil.  Apparently the white wire which is the ignition live wire for non-ballast ignition systems is retained in the wiring harness to accomodate vehicles with conventional ignition systems.  That'll save running a new wire and will keep things nice and neat if you can find it.

 

I've never had trouble starting a Mini with a conventional ignition system no matter how cold it's been so I'd ditch the ballast resistor.

Thanks again, will hunt for the correct feed to wire for this coil, and ditch the ballast. Have a new 12v sports coil in the post too, as this one is probably damaged by now. Will report back when all is sorted 

[cal844]

The 12volt feed isn't in the wiring harness. What needs to happen is

Cut ballast wire out of wiring loom

Fit new 12v wire then change to 13 v coil

[Chelsea_Pete]

The 12volt feed isn't in the wiring harness. What needs to happen is

Cut ballast wire out of wiring loom

Fit new 12v wire then change to 13 v coil

You're right, I've traced back the pink/white ballast and what I found was - 3 white wires spliced into it. One from the fuse box and 2 presumable to the ignition. 
Is this standard or has it been messed about with!?
If I want to run a new 12v feed to  the coil can i use one of those white wires?
Just trying to work out how to upload a photo..

[Chelsea_Pete]

Here's what I found: are any of those white feeds suitable to take for a standard non-ballast 12v feed?

Attached Files

•  DSC_07561-min.JPG   26.33K   5 downloads

[GraemeC]

That standard. I would personally snip he white pink from there and then re-wrap that joint.
Then take a fresh wire from the terminal on the fuse box where you’ve found the existing white wire connect to.

[cal844]

That standard. I would personally snip he white pink from there and then re-wrap that joint.
Then take a fresh wire from the terminal on the fuse box where you’ve found the existing white wire connect to.

I agree with this, best to cover the exposed copper and simply use a piggy back spade terminal to make the new connection direct from the fusebox

[unburntfuelinthemorning]

I agree with the above method of taking a live feed from the same side of the fusebox at the connection where the white wires connect will work nicely.

 

To quote Haynes though:

 

"To determine if a vehicle is equipped with a ballasted ignition system, check for the presence of a supplementary wiring harness, incorporating the white/pink ballast resistor lead, between the fuse block and the ignition LT terminal.

"The ballast resistor lead replaces the original coil feed.  The original lead is colour-coded white and is retained in the harness to accomodate vehicles not fitted with a ballasted system.  Do not connect this white lead to the ignition coil, it must remain taped to the harness."

 

Now this may be ******* but I thought it would be worth a look as it would provide an easy ready made solution to the problem without adding more wires - simply disconnect the white/pink wire and connect the white one.

[cal844]

I agree with the above method of taking a live feed from the same side of the fusebox at the connection where the white wires connect will work nicely.

To quote Haynes though:

"To determine if a vehicle is equipped with a ballasted ignition system, check for the presence of a supplementary wiring harness, incorporating the white/pink ballast resistor lead, between the fuse block and the ignition LT terminal.
"The ballast resistor lead replaces the original coil feed. The original lead is colour-coded white and is retained in the harness to accomodate vehicles not fitted with a ballasted system. Do not connect this white lead to the ignition coil, it must remain taped to the harness."

Now this may be ******* but I thought it would be worth a look as it would provide an easy ready made solution to the problem without adding more wires - simply disconnect the white/pink wire and connect the white one.

Having worked on a few ballast cars, I can say that the ballast wire is in with the main loom, which takes out the front loom if it melts

[unburntfuelinthemorning]

Yes I don't doubt that

 

 

I agree with the above method of taking a live feed from the same side of the fusebox at the connection where the white wires connect will work nicely.

To quote Haynes though:

"To determine if a vehicle is equipped with a ballasted ignition system, check for the presence of a supplementary wiring harness, incorporating the white/pink ballast resistor lead, between the fuse block and the ignition LT terminal.
"The ballast resistor lead replaces the original coil feed. The original lead is colour-coded white and is retained in the harness to accomodate vehicles not fitted with a ballasted system. Do not connect this white lead to the ignition coil, it must remain taped to the harness."

Now this may be ******* but I thought it would be worth a look as it would provide an easy ready made solution to the problem without adding more wires - simply disconnect the white/pink wire and connect the white one.

Having worked on a few ballast cars, I can say that the ballast wire is in with the main loom, which takes out the front loom if it melts

 

Yes, I don't doubt that but we are talking about disconnecting the ballast wire so that can't happen.  I'm saying use the white wire that is already there rather than adding an additional one and disconnect the ballast wire from the coil - unless this statement in the Haynes manual is false in which case a new ignition wire will need adding. 

Edited by unburntfuelinthemorning, 06 August 2018 - 08:54 PM.