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Coil wires

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StevenA

Jedi Trainee
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Put in a new coil... the old one showed 1.3 Ohms and the new oneis 3.1 Ohms... anyway the wires going to coil were set aside and mixed. The manual shows a schematic of the coil but doesn't have a + or - pole to tell which one goes where. I can trace the wires to locations by un-wraping them and following them... but thought I could save time if someone has a 76 Midget and can look. One set of wires is white with Black stripe and the other is white with Green stripe. Schematic shows W/B going to Dist and W going to Tach. If no answer I will just unwrap enough to tell which goes to dist and go from there. Sure would be easy if manuals would just print a + and a - on the picture (too much ink I guess)
Cheers, Steve
 
Thanks... this shows the 76 model to be 6 volt. Is that possible? I am assuming that the electronic ignition is also the seventies ? But my problem is solved... I have white with black and white with green and the schematic shows + and - sides of the coil. I looked on my other MGs but had to drive out to the storage barn to do so... this should be part of the manual anyway. I should have noted the wires when I removed them... just lazy and not awake.
Thanks
 
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by StevenA:
Put in a new coil... the old one showed 1.3 Ohms and the new oneis 3.1 Ohms...
Cheers, Steve<hr></blockquote>
Why did you change from 1.3 to 3.1 ohm coil?
D

[ 04-27-2004: Message edited by: Dave Russell ]</p>
 
The instructions assume that you have no ballast resistance in the feed to the coil. A ballast resistance, either a resistor or extra resistance in the coil feed wiring itself, would require a 6 volt coil such as the original 1.3 ohm coil. A non ballast system that has full battery voltage at the coil, would have no extra resistance & require a 3.1 ohm coil.

Since I don't know exactly what system & parts you have, with the ignition turned on, measure the voltage from the hot side of the coil to ground.

If the voltage is around 12 or 13 volts, you have a non ballasted system & should use the 3 ohm coil.

If the voltage is around 6 to 8 volts, you have a ballasted system & should use the 1.3 ohm coil.

If you use the ballast resistance with the 3 ohm coil, you are essentially putting 6 to 8 volts on a coil intended for 12 volts. the spark voltage will be lower than it should be.
D
 
Thanks... I am dumb as a rock sometimes. Instructions don't say anything even remotely refering to your note... I just had a blonde moment and went with them. I need to put the 1.3 ohm coil back on... and then see what happens
 
The instructions in the electronic ignition said that it required a 3.0 coil. I thought the one I had was OK but then just changed since it recommended 3.0
 
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