astonmos Posted June 7, 2011 Report Share Posted June 7, 2011 Evening, I have a 1973 TR6 (CR chassis/engine). Can anyone advise on where I can locate the ballast resistor as the coil has no indentification/markings. Any adivse would be greatly appreciated. -Graham- Quote Link to post Share on other sites
Yorkkie Posted June 7, 2011 Report Share Posted June 7, 2011 Evening, I have a 1973 TR6 (CR chassis/engine). Can anyone advise on where I can locate the ballast resistor as the coil has no indentification/markings. Any adivse would be greatly appreciated. -Graham- There will be an additional connection on the starter motor, this feeds 12v to the ignition during starting (when solenoid operated). Also you should be able to find a joint with 3 wires in the loom on the wheel arch on the nearside. I think the ballast resistor is a piece of resistance wire. If you check the coil it will be approx 1.5ohm instaed of 3 ohms. Andy Quote Link to post Share on other sites
poolboy Posted June 7, 2011 Report Share Posted June 7, 2011 If original, it would be a wire. It comes out of the harness behind the alternator and is conjoined with the 12 volt starting wire in a female spade connector that fits onto the coil's + terminal. The resistor wire is a solid core, not stranded, wire whose insulation is pink and white (k/w). The thing is, the wire was coverd with a woven cloth sheath, if still intact, may not allow the k/w to be visible.. The other wire, the 12 volt starting wire sharing the connector, is white and yellow. The coil you need for a ballasted ignition would be 1.5 ohm resistance. Quote Link to post Share on other sites
88V8 Posted June 7, 2011 Report Share Posted June 7, 2011 (edited) If you check the coil it will be approx 1.5ohm instaed of 3 ohms. It should be...... but sometimes, not realising there is a ballast, people fit a standard 3ohm coil, and then the plugs oil up.... As a double-check, attach your DVM to the + side of the coil, and turn the engine over by hand. If there is a ballast connected you will see the voltage flipflop between 12V and 8V. If no ballast, it will be a constant 12V. and... welcome to the forum. Ivor Edited June 7, 2011 by 88V8 Quote Link to post Share on other sites
poolboy Posted June 7, 2011 Report Share Posted June 7, 2011 It should be...... but sometimes, not realising there is a ballast, people fit a standard 3ohm coil, and then the plugs oil up.... As a double-check, attach your DVM to the + side of the coil, and turn the engine over by hand. If there is a ballast connected you will see the voltage flipflop between 12V and 8V. If no ballast, it will be a constant 12V. and... welcome to the forum. Ivor I might be wrong,Ivor, but over here with a ballasted ignition, the key has to be twisted to "START" for the coil to get 12 volts. The key has to be in the "ON" position (as if the engine were running) to get the 8+ volts. Quote Link to post Share on other sites
Yorkkie Posted June 7, 2011 Report Share Posted June 7, 2011 I might be wrong,Ivor, but over here with a ballasted ignition, the key has to be twisted to "START" for the coil to get 12 volts. The key has to be in the "ON" position (as if the engine were running) to get the 8+ volts. thats how it works here as well Quote Link to post Share on other sites
Steve P Posted June 8, 2011 Report Share Posted June 8, 2011 I just happen to have a photo of my balast resistor wire, so thought I'd share it. Cheers Steve Quote Link to post Share on other sites
88V8 Posted June 8, 2011 Report Share Posted June 8, 2011 I might be wrong,Ivor, but over here with a ballasted ignition, the key has to be twisted to "START" for the coil to get 12 volts. The key has to be in the "ON" position (as if the engine were running) to get the 8+ volts. Well, I thought so, and it was only quite by chance that I detected the ballast on my car, after months of plug oiling. I was setting the timing, hand-rotating the engine, and for some reason I had the DVM connected to the live input. Was most surprised to see the voltage oscillation which happened as the points opened & closed. While the starter is energised there is a full-time 12V, as you say. Since then, other members hunting the elusive ballast have reported the same phenomenon. Ivor Quote Link to post Share on other sites
poolboy Posted June 8, 2011 Report Share Posted June 8, 2011 I like to take the points out of the action when testing voltage to the coil. I prefer to use a ground that doesn't break, something like the engine block or the - terminal of the battery. I make an exception if I am wanting to test the ability of the points to make and break ground (earth) connection and then it's not necessary to use the coil+; any + will do. Quote Link to post Share on other sites
scorpio Posted November 4, 2011 Report Share Posted November 4, 2011 There will be an additional connection on the starter motor, this feeds 12v to the ignition during starting (when solenoid operated). Also you should be able to find a joint with 3 wires in the loom on the wheel arch on the nearside. I think the ballast resistor is a piece of resistance wire. If you check the coil it will be approx 1.5ohm instaed of 3 ohms. Andy Hi Guys Ive just fitted a new starting motor to my CR 1973 TR6, There are only 2 terminals ? Where should i fit the extra white wire which feeds 12v to the ignition during starting (when solenoid operated) ? Can i just tape it up and forget about it? it seems to start ok! Steve Quote Link to post Share on other sites
Steve P Posted November 5, 2011 Report Share Posted November 5, 2011 Steve, I did the same last year and left it disconnected. However soon after I fitted contactless points which came with a 12v coil. Cheers Steve Quote Link to post Share on other sites
scorpio Posted November 5, 2011 Report Share Posted November 5, 2011 Hi Steve What was involved, when changing to a 12v coil, I would like to do this, because i bought a coil and contactless points from AccuSpark™ electronic ignition module last month, and did not think i could use it? Regards Steve Quote Link to post Share on other sites
Steve P Posted November 5, 2011 Report Share Posted November 5, 2011 Steve, Just swap the coils over, fit the new points and your away. Steve Quote Link to post Share on other sites
scorpio Posted November 5, 2011 Report Share Posted November 5, 2011 What about the ballast resister? Steve Quote Link to post Share on other sites
scorpio Posted November 6, 2011 Report Share Posted November 6, 2011 A little more help with my CR 1973 TR6 please. After I fittedthe new Pre-Engaged Geared High Torque Starter Motor, I was left with a spare white and yellow wire with no terminal to fit it on, So because I am also fitting a new AccuSpark™ electronic ignition module and12volt coil pack.... Do i leave the white and yellow wire which gos to the distributor off and tape it up?Do i remove the ballast resister? Cheers Steve Quote Link to post Share on other sites
Ragtag Posted November 7, 2011 Report Share Posted November 7, 2011 (edited) A little more help with my CR 1973 TR6 please. After I fittedthe new Pre-Engaged Geared High Torque Starter Motor, I was left with a spare white and yellow wire with no terminal to fit it on, So because I am also fitting a new AccuSpark™ electronic ignition module and12volt coil pack.... Do i leave the white and yellow wire which gos to the distributor off and tape it up?Do i remove the ballast resister? Cheers Steve I'm not familiar with the new starter set up but from your posts, assuming that your car still starts and runs, this implies that the terminal that your Pink/White wire is connected to must be live in both the cranking and running conditions. The Pink/White wire is the ballast resistor. So.....if you fit the Accuspark coil and ignition module, you must disconnect the Pink/White wire from the starter and connect the Yellow/white wire. This bypasses the ballast resistor and will give a constant 12v at the coil end. Edited November 7, 2011 by Ragtag Quote Link to post Share on other sites
claymak Posted June 28, 2014 Report Share Posted June 28, 2014 I went round and round a bit on this and found this test to confirm ballast or no ballast good luck, Ken Quote Link to post Share on other sites
Nigel Lay Posted June 28, 2014 Report Share Posted June 28, 2014 Just make sure the points are closed when measuring the voltage Nigel Quote Link to post Share on other sites
claymak Posted June 30, 2014 Report Share Posted June 30, 2014 What if you have electronic points ? Do you know a better why to confirm if you have a ballasted system or not ? Regards, Ken Quote Link to post Share on other sites
peejay4A Posted June 30, 2014 Report Share Posted June 30, 2014 (edited) Put your multimeter on resistance. Disconnect the battery positive lead. Disconnect the wire from the loom to the coil (not the one going from the coil to the distributor). Connect the multimeter to the wire you just disconnected from the coil. Now connect the other multimeter lead to the positive battery cable. It should read open circuit. Turn the ignition switch on and measure the resistance. If it's 0.1 ish or less then you don't have a ballast. If it's reading more than 1 Ohm then you do. Edited June 30, 2014 by peejay4A Quote Link to post Share on other sites
RogerH Posted June 30, 2014 Report Share Posted June 30, 2014 ...or you could disconnect the +ve wire off the coil and short it to earth through a light bulb. Turn Ig on if you get 12V (battery volts) then it is not a ballast. If you get something lower than the battery volts (8 or 9) then it is a ballast wire. Roger Quote Link to post Share on other sites
peejay4A Posted June 30, 2014 Report Share Posted June 30, 2014 That's quicker. Use a fairly high wattage bulb though to make sure it drops enough volts to make the measurement valid. Quote Link to post Share on other sites
claymak Posted June 30, 2014 Report Share Posted June 30, 2014 5.271K ohms in the off position and 6.9 in the on position Thank you Quote Link to post Share on other sites
peejay4A Posted June 30, 2014 Report Share Posted June 30, 2014 If that's 6.9 ohms then I'd say you have a ballast wire. Quote Link to post Share on other sites
claymak Posted June 30, 2014 Report Share Posted June 30, 2014 Thanks - Looks that way ... can you help me through getting it out of the circuit ? I did run the car for 15 - 20 minutes this way is that an issue ? I still have 3 ohms on the ignitor (-; or should I order the 1.5 ohm and change it out ? that cloth insulation isn't looking that great at this point. Thanks again Ken Quote Link to post Share on other sites
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