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Triumph TR6 - Is my ignition coil wired in reverse?

Hi All,

After reading all the archives I am almost afraid to revive this subject but here goes:

On Saturday I was installing a Pertronix Ignitor in my 74-TR6 and things were going really well. I have a ballasted system so I attached the RED wire to the fuse panel (before the fuse) and the BLACK wire to the coil where the original points wire was connected.

My fist problem was when I tried to re-install the rotor, it looks like half of the plastic key/part inside the rotor shaft is missing and with the rotor slighty higher up due to the thickness of the Ignitor magnet it is not grabbing anymore. Problem should be solved with a new rotor, something I plan on trying later today.

Second and more important problem or question. In reading the archives and looking at the wiring diagram it looks like my coil is wired in reverse. The 12 Volt is connected to the (-) terminal on the coil and the black wire (originally from the points) now from the Ignitor is connected to the (+) terminal. Should this have been working at all? Is my coil connected in reverse?

Any advice would be appreciated.

Sylvain
S Demers

Hi Sylvain,
Yes it is wired up backwards.
The White 12V wire goes to + coil and the black Ignitor wire goes to - coil. The Red ignitor wire is +12 volts for the ignitor. I am non-ballast so I go directly to my coil with both red and black wires. Remember when getting power from the fuse block, pick one that is only live when the ignition is on.
Putting power to a Pertronix ignition system when connected backwards could do harm to the electronics.
Rick C
Rick Crawford

Hi Rick,

Thanks for the quick reply. Yes I did connect to a switched 12 Volt no problem there.

But any comments on how this inverted coil setup could have worked with the points???

Sylvain
S Demers

A coil that is connected backwards will still function, but not to it's full capacity. You probably have had a weak spark, but obvioulsy it was strong enough to make your engine run. It will work better, and give a hotter spark when connected properly. On a Neg. ground car the hot wire always goes to the + terminal, and the - terminal is connected to ground thru the points.
Ed Bell

Here's an update:

I installed the new rotor and turned the coil around and inverted the +/- wiring. The car started and runs beautifully. Blame the DPO for the coil mixup.

Now the next phase, spark plugs, spark plug wires and coil.

Thanks for the responses.

Sylvain

S Demers

Sylvain
Sorry, was typing a reply and got doing something else and must have closed the page down. I thought it might work backwards like Ed said and be a much lower spark. YA, she must be a happier camper. If you get the higher voltage coil (40,000V) you can up the spark plug gap to 40 thou.
Rick C
Rick Crawford

Sylvain
I just learned of and purchased from a Triumph parts supplier in Newmarket. email me if you want more details.
Cheers
Pete
Pete Russell

Tonight I went ahead and replaced the spark plugs and spark plug wires and what a difference that made. The car is running better than ever, I must have had a bad spark plug wire at least. The idle is so much smoother and there is a noticeable increase in power. When I removed the spark plugs I found 3 different kinds ??? 3-Champion, 2-NGK and 1-Motomaster.

Can't wait to see what other surprises the DPO left me.

Sylvain
S Demers

Sylvain,
Glad to hear she is run better. Now you need to tune the other side of the engine.
Rick C
Rick Crawford

There is a simple check to see if a coil is wired backwards. Pull the coil wire loose from the distributor cap and hold it about 1/4 inch from the engine block. Insert a sharpened pencil tip into the gap. Have someone crank the engine. If the spark is between the pencil and the block, you have it right. If between the pencil and the wire end it is backwards. If backwards the coil becomes a step down transformer instead of a step up. It'll work, it's just not as efficient. Why isn't there a spark on both sides of the pencil? Rule number one in my classroom: "Don't ask any questions I don't know the answers to."
Joe Justice
Joe Justice

I don't know. Does it suck up the spark?
skikir

This thread was discussed between 19/06/2006 and 14/07/2006

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