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Joined: Aug 2001
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Hi Guys, 1967 T120 Pazon, POD, 12 volt battery wired positive ground, single position on off switch for ignition. Single point ground.

Hoping for a little insight. Just finished a two day custom wiring job and hoping someone has seen this problem before.

I am not seeing any spark when kicking the engine thru, or touching the trigger leads together, but it sparks when I shut off the ignition switch. This leads me to believe (maybe incorrectly) that the plugs, plug wires, switch and coils are all working. I'm using a single point ground for both lighting and ignition, and the lighting is also working fine. battery is new and holds over 12v under load.

Notes:

1. I see constant voltage 9.7v at the negative terminal of coil 1 (Pazon black wire connection) when ever the ignition switch is on.
2. The 9.7v @ negative terminal of coil 1 (Pazon black wire connection) jumps to around 11.7 when kicking thru
3. The voltage jumps up to 12.7 at the same moment I shut the ignition switch off the the plugs both spark.
4. Lastly if I have the meter just on the battery a see the voltage jump up into the 14's at the same moment I shut off the switch and the plugs spark. Not sure if that measn anything, but figured I would include it just in case.

Any and all help is greatly appreciated.
Thanks -Rob

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That 9.7V is concerning, should be measuring close to battery volts minus about a volt(so say ~11.6V) between the 1st coil –ve and battery +ve.

Is the battery definitely good, ‘cos we’ll be wasting a lot of time if it’s not?

It seems the Pazon box is working as it sparks when supply is switched.

It is possible that there is a simple error in the new wiring.

Perhaps disconnect the lighting wires nearest to the battery –ve, to focus on the ignition system first?

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Coils wired in series?

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Quote
1. I see constant voltage 9.7v at the negative terminal of coil 1 (Pazon black wire connection) when ever the ignition switch is on


you shouldn't be able to read voltage off the black wire with a voltmeter ever
the black wire is the power output for the transistor box
but only passes power ... for milliseconds at a time . .. ( too quickly for a voltmeter to catch )
the black wire flashes voltage
once at power up
once at power down
and once for each negative wave signal input as the spinning timing rotor passes the timing stator .

these flashes can be read as Sparks through the coils ... but not as voltage with a voltmeter .

you need to check your wiring ( coils probably not wired in series )

the pazon positive ground wiring
is the same as the negative ground wiring

... the switch side is just moved from
positive battery terminal to the negitive battery terminal
......
[Linked Image from triumphbonneville120.co.uk]

Last edited by quinten; 01/19/21 11:17 pm.
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Thanks!

Voltage drop - The 9.7v at coil #1 jumps up to the low 11's when I kick it thru, but I agree, and was surprised to see a voltage drop on a freshly wired bike using only a single one position switch to get juice from the battery to the Pazon white. The black lead from the Pazon is a single uninterrupted lead directly to the coil.

battery - The battery was tested at the same time with a high quality battery tester that puts the battery under load and it showed 12.71v 138CCA and 90% state of charge.

Pazon box - One of the trouble shooting procedures in the Pazon books states if you don't get sparks when touching the trigger wires together it may be the ignition module. Of course it also states it could be the battery, switch, grounding, and wiring too.

Wiring Error - It is certainly possible there is a simple wiring error. Was actually hoping my symptoms were indicative of a particular mistake I may have made.

Lighting circuit - I will disconnect the lighting circuit, and possibly the POD to simplify the wiring.

I appreciate your help,
-Rob

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Coils are wired as per the diagram you posted above for positive ground. (I am also looking at the same book) and the bike and just triple checked...

What I have is -Black Pazon wire to Neg terminal of coil #1 / black jumper from Coil #1 Pos terminal to the Neg Terminal of Coil #2 / Red wire from Pazon to Pos Terminal of Coil #2/ Ground wire running from Coil #2 Positive terminal back to the battery positive and to ground lug on the engine

Thanks for your help. I though I wasn't suppose to see volts at the coil by just flipping the ignition switch.

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pull the black wire from the T-box wire ... from its coil connection
with ingition on ,
read the voltage at the black wire ... should be zero .

if you have voltage
the box is bad ... and I apologize for saying your wiring was suspect .

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Pulled the black from the Pazon off the coil #1 Neg Terminal, hooked up the meter, flipped the switch, and yup full battery voltage at the black lead from the Pazon. Luckily I have a spare box handy, not so lucky is its a custom build so all the wiring his been tucked away in tidy PVC sheaths and now needs to come back out. (ugh) Lastly you Sir have helped me enough times that you may always assume my wiring is suspect.

Many thanks
-Rob


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