Jump to content


Photo
- - - - -

Does My Mini Have A Ballast Resistor Or Not?

electrical

  • Please log in to reply
25 replies to this topic

#1 Chrome_GT

Chrome_GT

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 78 posts

Posted 24 May 2015 - 06:24 PM

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



#2 CityEPete

CityEPete

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,920 posts
  • Location: On my soapbox....

Posted 24 May 2015 - 06:31 PM

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.


#3 carbon

carbon

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,590 posts
  • Location: UK

Posted 24 May 2015 - 06:59 PM

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.



#4 CityEPete

CityEPete

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,920 posts
  • Location: On my soapbox....

Posted 24 May 2015 - 07:14 PM

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 :-)

#5 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 24 May 2015 - 07:52 PM

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.



#6 KernowCooper

KernowCooper

    Sparkie

  • Mini Docs
  • PipPipPipPipPipPipPipPipPipPip
  • 7,847 posts
  • Name: Dave
  • Location: The South West
  • Local Club: Kernow Mini Club

Posted 24 May 2015 - 08:32 PM

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



#7 CityEPete

CityEPete

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 3,920 posts
  • Location: On my soapbox....

Posted 25 May 2015 - 09:14 AM

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.



#8 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 25 May 2015 - 12:04 PM

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.



#9 Podman

Podman

    Mini Mad

  • Members
  • PipPipPipPip
  • 201 posts
  • Location: Llandudno
  • Local Club: Snowdon Minis

Posted 28 May 2015 - 09:17 PM

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

#10 cal844

cal844

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 9,540 posts
  • Location: Ballingry, Fife
  • Local Club: TFMOC

Posted 28 May 2015 - 09:20 PM

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 



#11 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 29 May 2015 - 02:50 AM

 

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?



#12 KernowCooper

KernowCooper

    Sparkie

  • Mini Docs
  • PipPipPipPipPipPipPipPipPipPip
  • 7,847 posts
  • Name: Dave
  • Location: The South West
  • Local Club: Kernow Mini Club

Posted 29 May 2015 - 12:42 PM

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



#13 Chrome_GT

Chrome_GT

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 78 posts

Posted 29 May 2015 - 09:02 PM

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



#14 Podman

Podman

    Mini Mad

  • Members
  • PipPipPipPip
  • 201 posts
  • Location: Llandudno
  • Local Club: Snowdon Minis

Posted 30 May 2015 - 07:05 PM

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

#15 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 30 May 2015 - 09:17 PM

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.







Also tagged with one or more of these keywords: electrical

1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users