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Figuring out my ignition wiring

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cbez Cole B
Fallbrook, California, USA   USA
I test wired everything with the new coil (still on points) and it seemed to work. Still not sure about this mystery yellow wire.

I tested it without it and the car started fine and nothing in the cabin stopped working that I could find.



1971 Triumph Spitfire MK 4



Edited 1 time(s). Last edit at 2017-11-10 05:36 PM by cbez.

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20171110_153245.jpg    50.7 KB
20171110_153245.jpg

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
In reply to # 1497207 by cbez 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?

Test the wire for voltage. It could be 12v comming in from somewhere or it could be picking up ignition controlled power to power something else (like a radio)

Where does the other end go? It looks like it has been added by a PO, so I doubt it is bound into a loom.

cbez Cole B
Fallbrook, California, USA   USA
In reply to # 1497220 by Tonyfixit
In reply to # 1497207 by cbez 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?

Test the wire for voltage. It could be 12v comming in from somewhere or it could be picking up ignition controlled power to power something else (like a radio)

Where does the other end go? It looks like it has been added by a PO, so I doubt it is bound into a loom.

It goes in under the pdwa, wanders around, joins a loom, then as best as I can tell goes into radio. But when I unplug it the radio still works so I may have followed it wrong. I can't find anyone else under the dash powered by a small yellow.

0 voltage to the wire.



1971 Triumph Spitfire MK 4



Edited 1 time(s). Last edit at 2017-11-10 06:09 PM by cbez.

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colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, Colorado, USA   USA
1979 Triumph Spitfire 1500 "Spitty"
no voltage with the key on, but pull it off the coil, could be 12 volts when the starter is energized ?

In reply to # 1497224 by cbez It goes in under the pdwa, wanders around, joins a loom, then as best as I can tell goes into radio. But when I unplug it the radio still works so I may have followed it wrong. I can't find anyone else under the dash powered by a small yellow.

0 voltage to the wire.

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
You shouldn't have that many wires.

Someone probably didn't abandon prior runs or was putting in taps to things unrelated to ignition.

cbez Cole B
Fallbrook, California, USA   USA
ok so if I put the yellow wire and choke wire somewhere else, what's the best/smartest space?



1971 Triumph Spitfire MK 4

colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, Colorado, USA   USA
1979 Triumph Spitfire 1500 "Spitty"
Still need to test that yellow wire that is on the coil positive? if it has no power from it with the key on, perhaps that's the one bypassing the resistor and has power when the engine is started (12 volts from the starter solenoid) to the coil, and if it is then it's not needed because you will have 12 volts from another source. If the yellow doesn't have voltage from the solenoid it must supply something else, could leave it, but need to find what it's for eventually.

New coil in, engine started (where did it get power? was it coming from the wires on the resistor ?).
The new coil is a 3.0 ohm so it needs full 12 volts (no resistor).

Petronix replaces the points in the dizzy, connect 2 wires to coil as instructions.

In reply to # 1497260 by cbez ok so if I put the yellow wire and choke wire somewhere else, what's the best/smartest space?



Edited 1 time(s). Last edit at 2017-11-10 10:21 PM by colodad.

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cbez Cole B
Fallbrook, California, USA   USA
In reply to # 1497273 by colodad Still need to test that yellow wire that is on the coil positive, if it has no power from it with the key on, perhaps that's the one bypassing the resistor and has power when the engine is started (12 volts from the starter solenoid) to the coil, and if it is then it's not needed because you will have 12 volts from another source. If the yellow doesn't have voltage from the solenoid it must supply something else, could leave it, but need to find what it's for eventually.

New coil in, engine started (where did it get power?), The new coil is a 3.0 ohm so it needs full 12 volts (no resistor). Need a key switched 12 volt wire to the coil positive from somewhere, choke wire could connect to it too.

Petronix replaces the points in the dizzy, connect 2 wires to coil as instructions.

In reply to # 1497260 by cbez ok so if I put the yellow wire and choke wire somewhere else, what's the best/smartest space?

good point, I will test it with the key full turned tomorrow. However having stalked it I don't think it goes to my ignition switch. The 'bypass' wire should be straight from solenoid to coil at least according to the wiring diagram I have. I think it may be in line with the ballast wires bundle.

Engine got power from the yellow/white wire that was in the bundle that formerly went through the ballast resistor. I joined them together where the resistor used to be.



1971 Triumph Spitfire MK 4

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
Normally the white wire with the yellow tracer delivers 12v to a 6v coil as a boost during the time the starter is cranking.

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cbez Cole B
Fallbrook, California, USA   USA
That's the thing the WY to the coil is coming out loomed together with the wires to the resistor though.

Here's the cutout of the ignition section of the wiring diagram I'm using. Apparently they are accomplishing the ballasted 12v and the bypassed higher starting amperage with the same wire.



1971 Triumph Spitfire MK 4


Attachments:
starter wiring.jpg    10.7 KB
starter wiring.jpg

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1497224 by cbez as best as I can tell goes into radio. But when I unplug it the radio still works so I may have followed it wrong. I can't find anyone else under the dash powered by a small yellow.

Sounds about right. It's yellow because that's what color the PO (DPO) had in a junk box.

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