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dat260

New Coil

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Iam in the process of installing an new ignition coil that came with its own white resistor block. It has a wire that goes from resistor + to + on the coil.

My issue is that the new resistor as two attachment point were as my original resistor has three attachment point. (Early 74/260Z).

The original connections goes like this; the small cylinder (condenser?) is connected to the + of the coil than a blue wire from harness goes to coil negative. White/black wire from resistor negative to + coil

Black/White wire from harness goes to + resistor

Black/Blue from harness to its own pole on resistor.

Black wire from harness to - resistor to positive coil via white/black wire. (Black and White/black connected together at the resistor negative).

My question is how to I attach all the wire to the new coil and resistor which has only two attachment point?

 

Thanks in advance.

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I know the solution. I just won't be at my computer to type it up for a couple of days. Respond to this thread on Sunday if you haven't received a solution from someone else.

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I would use the original ballast resistor unless it is bad. The original ballast is wired such that the starter bypass only shunts one section of the ballast. Presumably, this is to keep the circuit resistance large enough to protect the electronic ignition module from an overload during cranking. Make sure your new coil has the correct primary resistance (0.5 ohms).

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If you're running electronic ignition, either pertronix or a matchbox, eliminate the ballast so you get the full 12 volts at the spark plugs! The. Ballast is only in there to prevent burning out your points


Sent from my iPhone using Classic Zcar Club mobile

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Edit 2 - I screwed up.  You can get the Start resistor bypass by connecting black/blue to the same terminal as white/black.  Black/blue is Start power, black/white is Run power, and white black is just the line from resistor coil positive, to supply coil power.  Looks like Nissan used half a ballast resistance for Start power.

Deleted, realized I didn't understand what the OP was describing.   Edit - found it, attached.  Black/blue and black/white would connect together to one end, and white/black connects to the other.  But you'll lose the Start bypass which will drop coil current during starting.

1974 is the first Z with electronic ignition but they still used a ballast.  The condenser is to save the points, the ballast is to control current through the system.  They're pretty interesting, the resistance changes as they heat up, due to current, to drop current.  Self-actuating.  But the other issues of which coil and which ignition system and which resistor you should use can't really be answered.

You could measure resistance of the two and decide if there's any benefit to the new one.  The Starter bypass might be helpful, although they got rid of it in the later years with more powerful ignition modules.

Why'd you get a new coil anyway?

 

Found it.PNG

1974 electronic.PNG

Edited by Zed Head

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Hi Zed Head,

I got a new coil because mine was all rusted and it looked like it was leaking at one point. The car always started fine but my tach started to bounce and now its pinned a 10k and it does not move anymore. When I tested the primary and secondary it was a little below the factory specs.

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23 hours ago, SteveJ said:

I know the solution. I just won't be at my computer to type it up for a couple of days. Respond to this thread on Sunday if you haven't received a solution from someone else.

Thanks Steve, I wont work on my car til next week. Looking forward to your reply.

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22 hours ago, Jarvo2 said:

If you're running electronic ignition, either pertronix or a matchbox, eliminate the ballast so you get the full 12 volts at the spark plugs! The. Ballast is only in there to prevent burning out your points


Sent from my iPhone using Classic Zcar Club mobile

Iam using the factory ignition system. Its has points and electronic ignition, I think. I know it has an electronic box. Whats a ballast? Is it the white ceramic block or the little cylinder connected to the + coil?

 

Edited by dat260

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7 minutes ago, dat260 said:

Hi Zed Head,

I got a new coil because mine was all rusted and it looked like it was leaking at one point. The car always started fine but my tach started to bounce and now its pinned a 10k and it does not move anymore. When I tested the primary and secondary it was a little below the factory specs.

Beermanpete had the best suggestion then, in Post #3.  Just make sure that the coil specs match.

That's probably not the problem with your tach though.  But good luck.

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Thank you, I will check that. If it does not cure my tach problem then I will leave it alone. The car ran fine with the original coil.

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What brand and model of coil did you get?  We can tell you if it's right.

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Do you have a meter?  You can check the specs against factory.  I'm guessing that you're on a budget?  That's not one of the Rock Auto products for the 260Z.

Here are the specs for the 260Z coil and the resistor.  Looks like Datsun was shooting for about 1.5 to 2.0 total.  I can't find specs for the C-632 out on the internet.  Amazon's site says it's not a fit for the 260Z but without specs, who knows.

 

74 coil.PNG

Edited by Zed Head
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The primary stock coil reading is 1.6 and the secondary is 13.55. The new coil C-632 is, primary 2.0 and the secondary 9.68

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On ‎29‎/‎06‎/‎2017 at 3:49 PM, SteveJ said:

I know the solution. I just won't be at my computer to type it up for a couple of days. Respond to this thread on Sunday if you haven't received a solution from someone else.

Hi SteveJ

Iam curious about your solution.

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