Section : Electrical Equipment

Alternators, dynamos, lights, wipers, etc.

Ballast resistor wire

Posted By : Grant Brooks, 09-Jun-2003, 04:04pm

I am planning to fit a Lucas sport coil to my '77 1500. I understand that I need to remove/bypass the ballast resistor wire in order to get the benefit from this coil.

Has anyone carried out this operation? Any suggestions as to the best/easiest way to achive this? If possible I'd rather keep the wire in place in case I wish to revert to standard spec in future.

Also, any advice regarding spark plug gaps after fitting the coil?

Followups :

Ballast resistor wire

Posted By : Chris Wilson, 17-Jun-2003, 07:26pm

Grant,

DON'T remove the ballast wire! I did and the car wudn't fire up!! Luckily I thought that might happen so I didn't remove the ballast wire completely and just re-soldered a new connector on to the ballast wire and shoved it back onto the 2nd terminal.

I believe the ballast wire just needs to be bypassed by another wire routed from any white? wire from the ignition? Haven't got round to doing it myself yet! And am also interested in the best plug gap to have once the coil is functioning at it's best! I have my plug gaps set at 70 (metric) but not sure if I can improve on that gap?

Anyone out there any suggestions? BTW - I've got an Aldon Flamethrower coil fitted.

Regards

Chris

1975 1500
- Ballast resistor wire
  
  Posted By : David Chudziak, 18-Jun-2003, 09:17pm
  
  more info at:
  
  http://www.vtr.org/maintain/ballast.html
  
  Connect a new wire to the + terminal of the coil and splice / connect this to the nearest white wire (try the fuse box). No need to remove / disable the resistance wire, because it will now be permanently bypassed.
  
  Regards
  David
  - Ballast resistor wire
    
    Posted By : David Chudziak, 18-Jun-2003, 09:32pm
    - Ballast resistor wire
      
      Posted By : Grant Brooks, 27-Jun-2003, 01:53pm
      
      Mark/Chris/David
      
      Thanks for the help guys, I'll let you know how I get on.
      
      Thanks again.
      
      Grant Brooks
      - Ballast resistor wire
        
        Posted By : Stephen Airey, 30-Jun-2003, 01:06pm
        
        Just to let you guys know that I changed my coil at the weekend from the 6v to the 12v, using the advice here - I tapped a 12V feed off a white wire behind the fuse box and connected it to the + terminal of the coil, leaving all other connections in place. It works great and has solved a couple of problems I had with the car: - slow start up of the rev counter & intermittent cutting out
        there is also noticably more power and pull and the car sounds smoother and quieter! I reset the spark plug gaps to 0.8mm (80 metric) and also fitted new HT leads at the same time.
Ballast resistor wire

Posted By : Mark Astley, 19-Jun-2003, 02:40pm

I've done something similar to my MkIV, however I bought a dedicated 6v sports coil and left the ballast resistor in place. It is a Lucas coil also, bought from Moss, they are a bit more expensive than the 12v version probably cos they don't sell as many.

It was also at this moment that I discovered that my car had an incorrect 12v coil since I bought it. Made massive improvement to the engine power and torque.

I put my plug gaps up to 30 thou and it's been fine, might up them a tad more soon.

yours
mark
- Ballast resistor wire
  
  Posted By : Chris Wilson, 22-Jun-2003, 12:22pm
  
  Mark/David,
  
  Thanks for the tips. I've finally got round to doing it this morning! Took the feed from the ignition switch white wire, disconnected the ballast wire and taped it up out the way and I've opened up plug gap to 32 thou. Haven't taken car for a decent run yet but everything seems to be fine!
  
  Regards
  
  Chris
  
  75 1500