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Figuring out my ignition wiring

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Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
For this test it's easier to temporarily disconnect the heavy cable wire going to the starter.

Hook up a test light to the white wire with the yellow tracer going into the coil and see if it has power with the key on. See if it gets brighter when you turn the key and activate the starter solenoid.

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colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, Colorado, USA   USA
a cloth wetted with breake cleaner will clean up those dirty wire colors.


Attachments:
multimeter at walmart $10.08.jpeg    36.5 KB
multimeter at walmart $10.08.jpeg

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
Scraping them with an X-Acto and scrubbing them DRY with a steel scrubber works too.


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cbez Cole B
Fallbrook, California, USA   USA
I have them clean ish and labeled by color above. Going to test with multimeter now.



1971 Triumph Spitfire MK 4

cbez Cole B
Fallbrook, California, USA   USA
Ok so I have 12v to all of the wires with the ignition turned. The middle key setting makes the voltage slowly rise to 12 while the start setting makes it jump to 12 immediately.



1971 Triumph Spitfire MK 4

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
The problem (I think) with testing with a multimeter is the resistance wire will still read 12v because the meter will not be drawing a load.

The light bulb method might be better. Check the brightness at full 12v, then check it when suppiled by the (possible) resistance wire.

cbez Cole B
Fallbrook, California, USA   USA
I don't think I have a resistance wire because my year had the ballast resistor and mine appears tool be working fine.



1971 Triumph Spitfire MK 4

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Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1497186 by cbez I don't think I have a resistance wire because my year had the ballast resistor and mine appears tool be working fine.

Classic dual voltage then.

White wire to ballast resistor.

Short jumper from the other side of the ballast resistor to + side of coil.

White with yellow stripe from boost on starter solenoid to + side of the coil.

cbez Cole B
Fallbrook, California, USA   USA
So back to beginning, what is safest way to wire everything up with the new 3 ohm coil?



1971 Triumph Spitfire MK 4

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lef2wander Avatar
lef2wander Gold Member James Thomas
hatfield, ma, USA   USA
In reply to # 1497192 by cbez So back to beginning, what is safest way to wire everything up with the new 3 ohm coil?

12v everywhere. A 3ohm coil requires 12v all the time. From all sources.



Edited 1 time(s). Last edit at 2017-11-10 03:31 PM by lef2wander.

cbez Cole B
Fallbrook, California, USA   USA
In reply to # 1497198 by lef2wander
In reply to # 1497192 by cbez So back to beginning, what is safest way to wire everything up with the new 3 ohm coil?

12v everywhere. A 3ohm coil requires 12v all the time. From all sources.
Right my question is what do I actually do to my existing wiring to make it work smart and safe.



1971 Triumph Spitfire MK 4

colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, Colorado, USA   USA
testing with a volt meter connected to the coil positive,
pull dizzy cap center HT wire and ground it,
with key on the volts will be 12, but when you ground the coil negative, volts are dropped if there is a resistor, because your pulling voltage through the coil.

In reply to # 1497185 by Tonyfixit The problem (I think) with testing with a multimeter is the resistance wire will still read 12v because the meter will not be drawing a load.

The light bulb method might be better. Check the brightness at full 12v, then check it when suppiled by the (possible) resistance wire.


Attachments:
cwIMG_2383 meter connected to coil positive, key off.jpg    42.4 KB
cwIMG_2383 meter connected to coil positive, key off.jpg

cwIMG_2384 meter connected to coil positive, key on.jpg    35.7 KB
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cwIMG_2386 meter connected to coil positive, key on, coil negative to ground, 5.19 volts from a resistor.jpg    48.4 KB
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colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, Colorado, USA   USA
Cole, doesn't the instructions show petronics works with or without the resistor, it depends which coil you have to install 12V or 6V, 3.0 ohm or 1.5 ohm.


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petronix with 3.0 ohm coil.JPG    44.2 KB
petronix with 3.0 ohm coil.JPG

petronix with 1.5 ohm (6 volt) coil.JPG    34 KB
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Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1497192 by cbez So back to beginning, what is safest way to wire everything up with the new 3 ohm coil?

White directly to +.

cbez Cole B
Fallbrook, California, USA   USA
Ok and does anyone know what the small yellow wire is doing, (not near the resistor) because now with the extra pertronix wire I'll have six wires at my coil...

Is that the wire that bypasses the resistor for extra ignition amps, or is that one bundled in with the ones near the resistor?



1971 Triumph Spitfire MK 4


Attachments:
20171110_140609.jpg    52.2 KB
20171110_140609.jpg

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