25 replies to this topic

[Chrome_GT]

71 1000cc (Now 1312)

A few years ago i had trouble starting my Capri. It turned out i had fitted a coil intended for a non ballasted system to the Capri which has a ballast. This lead to a weaker spark, occasional cutout, fdifficulty starting.

It's been many years since i had the mini going properly and i wonder if did the same thing. 

Cheers

[CityEPete]

You need to see what colour wires are at the coil, white with a pink stripe or just plain pink is the ballast wire, it then has an extra wire (yellow i think?) going to the starter solenoid that puts full voltage to the coil during cranking to eliminate the problem you had with the Capri. Now here's the rub, it could have a pink wire but not be ballasted if someone has peeled the loom back and removed the ballast part or if it's burnt out at some stage and been bypassed so test the voltage, 9v coil + to earth with the ignition on and the car running would suggest a ballasted system and the correct coil needs to be in place.

Edited by CityEPete, 24 May 2015 - 06:33 PM.

[carbon]

If it's still using the original 1971 wiring then it won't have a ballast resistor fitted.

 

Would also originally be fitted with dynamo.

[CityEPete]

The haynes book shows some early ballast looms, earlier than I thought for sure. Could have gained a stand alone ballast and ballast coil in 44 years, had a new front loom or general bodgery, I presume nothing these days

[dklawson]

It is easy enough to check.  You will need a jumper wire and a multimeter set to measure volts.

 

Connect the jumper wire between coil (-) and earth.

Turn the ignition key to "run".

Measure the voltage between coil (+) and earth.

If you measure about 12V, the car has wiring for a standard ignition coil.

If you measure 6V to 9V, the car is wired for a ballast coil.

 

Don't forget to turn off the ignition and remove the jumper wire.

[KernowCooper]

Be odd to see a 71 car ballasted but Dougs info above will confirm

[CityEPete]

Once that is confirmed either way the main thing is to make sure you have the right coil anyway as that is the thing that could have been fitted wrongly by someone!

 

Test across + and - (CB and SW on some coils) with a multi meter set on resistance,

 

3 ohms is a normal 12V non ballast coil.

1.5 ohms is a ballast coil.

1.0 ohms is a coil for the factory electronic ignition cars like my 1995 Mayfair.

[dklawson]

Minor footnote to CityEPete's post.  Mark and disconnect the low-tension wires from the coil before you make your resistance measurements.  You can occasionally get bogus measurements wit the wires attached.

[Podman]

I've connected the voltmeter to the coil +ve wire and earth, with ignition on its showing 6v.

[cal844]

I've connected the voltmeter to the coil +ve wire and earth, with ignition on its showing 6v.

Faulty connection or a very worn ignition barrel imo, others will advise 

[dklawson]

 

I've connected the voltmeter to the coil +ve wire and earth, with ignition on its showing 6v.

Faulty connection or a very worn ignition barrel imo, others will advise 

 

 

Assuming the points are closed or the jumper wire from coil (-) to earth is in place, 6V is indication that the car has wiring for a ballast coil.  Podman, the last questions are, did you measure the resistance across the low-tension terminals of the coil you are using and what colors are the wires on the coil terminals?

[KernowCooper]

Because this keeps cropping up I have put a post in the FAQs electrical section Here http://www.theminifo...ignition-check/

[Chrome_GT]

Excellent, Thanks Guys. I'll look into this over the weekend based on your suggestions.

[Podman]

Ok. Wires are white, and white and black. Still no spark though. Do I take it that its a ballast coil then?

[dklawson]

Measure everything again after you have cleaned the connections and confirm the wire colors again.  Make sure the white wire on the coil is really white, not pink in any way.

 

In Lucas wiring, white wires (and I mean white, not off white or pinkish) is for full 12V, switched, and unfused.

The white/black wire goes between the coil (-) terminal and the points in the distributor.

Therefore you should have a "standard" 3 Ohm coil for your car's wiring (based on the wire colors you mentioned).

 

If your car has 6V on coil (+) with the points closed or test jumper wire in place... something is wrong with the supply to the coil.