Gremlins in my Fairlady's Ignition System

[dasmoover]

I think that blue wire is the key. I didn't go in to all of the details of the blue wire but it also runs to the ignition module and the tachometer, branching off to each along the way.

I think that you should check the wiring diagram and get that blue wire connected to where it should be, before buying any parts. Does your tachometer move when you're cranking the engine? That would be a clue.

Here's a picture and a link to its source. It's 1976 but 1977 is essentially the same.

http://www.classiczcars.com/forums/open-s30-z-discussions/36494-free-full-color-wiring-diagram-1976-280z.html

Tach has no response. This sounds like it would be the short in my ignition system.

I will take a look at the diagram and see where it is supposed to connect and attach it tonight.

Thank you!

[Zed Head]

Not a short. No connection at all. The blue wire runs to the ignition module to make and break the electrical circuit to the coil, to provide spark. That's why you have no spark. It also branches off to the tachometer. And the ECU, to provide the signal for injection.

Zoom in on the lower left of the picture I provided and you'll see the ballast resistor, coil, and the blue wire.

[dasmoover]

So it attached to the negative terminal on the ignition coil? That's what it's looking like. I have the correct wiring on my ballast. Just missing the second one going to my negative end on the coil.

[dasmoover]

I've checked each wire going to the ballast they all return to the harness.

Here is a correct 1977 diagram. I still have an extra blue wire that goes back into the harness.

It has newer blue electrical tape indicating it has been messed with.

Any leads as to what this wire could be for...

[Zed Head]

Just missing the second one going to my negative end on the coil.

That may be the most important wire of all. Did you complete that circuit?

Note in your picture the blue wire with the bullet connector to the BCDD solenoid. Maybe that's your extra wire.

[dasmoover]

The car has been wired to the specifications of the diagram I attached to my previous post. There is the negative going to the ballast. I have a black wire that jumps from the condenser to the BCDD as noted in pictures of first post. (see black wire with bullet going straight to condenser)

[Zed Head]

One problem here is that you've had things disconnected and it's not clear that they were put back correctly. Also, your descriptions are a little different with the use of the word "spark". Does that mean an actual spark, like you're holding the wire close to its connection to see if a spark jumps? It's also not clear if you connected something backwards and blew a fusible link or fuses. What does this mean - "I flicked on the engine bay light and my fusable links sparked and sparked the wire going to the condenser on ALT.?

Testing continuity of the circuits with a meter would be a good idea, since you've had so many things disconnected. If you confirm that you have continuity to the ignition module, and power at the coil with the key On, then SteveJ's suggestion about the HEI module is definitely an inexpensive way to get back on the road. I have one on my car. But I would spend some time with a meter and the wiring diagram first.

[EuroDat]

Testing continuity of the circuits with a meter would be a good idea, since you've had so many things disconnected. If you confirm that you have continuity to the ignition module, and power at the coil with the key On, then SteveJ's suggestion about the HEI module is definitely an inexpensive way to get back on the road. I have one on my car. But I would spend some time with a meter and the wiring diagram first.

My ignition started playing up about two months ago. It started missing and stalling then would not start at all until it cooled down. Im now running a HEI module mounted on the coil bracket. It was a quick and easy $15 fix. Im also rebuilding the old ignition module with another HEI Module to clean up the engine bay and move the unit back under the dash.

I can post some photo's.

Chas

[dasmoover]

Let me be as concise as possible. A few weeks ago I placed a battery from my 84 300zx because the one it had was dead, before turning the engine I flicked on the engine bay light and live sparks flew from the battery down to the fusible link and effectively melting it. It also sent the electric charge down to the alternator and it caused some smoke. Since then I have replaced all 4 fusible links and can confirm voltage on all 4. I'm still concerned about that missing connection though.

I will take more pictures tomorrow that accurately describes the the wiring setup that the car has now. I can confirm I am not getting SPARK from the ignition coil to the distributor. I am getting continuity on both pos and neg on the coil.

[SteveJ]

Uh oh. That sounds like you reversed the terminals on the battery.

[Zed Head]

That's better, thanks for clarifying. It's great that you're diving in to an area you're not familiar with. In your first post you said that you removed the battery, and installed a new one. Maybe you got the connections correct the second time.

There are actually five fusible links. There's one more on a line directly from the battery to the EFI system. It's green and has a white plastic connector on each end. It's inline on a wire directly from the positive terminal. You can see it in picture number 4 in your first post.

On terminology - continuity is measured between two points in a circuit. So "continuity on the pos and neg of the coil" doesn't really mean anything. Continuity between those two points is normal, but what you really want is resistance between those two, and continuity between others. Also, voltage readings from several areas would be very helpful. Do you have a meter?

If you do have a meter, one test you could do is to turn the key on and see if you have battery voltage at the negative post of the coil. Maybe you already did that and that's what you meant by continuity?

You really need to post a picture of the top of the coil and the ballast resistor all in one frame.

Edited July 4, 2014 by Zed Head

[dasmoover]

That's better, thanks for clarifying. It's great that you're diving in to an area you're not familiar with. In your first post you said that you removed the battery, and installed a new one. Maybe you got the connections correct the second time.

There are actually five fusible links. There's one more on a line directly from the battery to the EFI system. It's green and has a white plastic connector on each end. It's inline on a wire directly from the positive terminal. You can see it in picture number 4 in your first post.

On terminology - continuity is measured between two points in a circuit. So "continuity on the pos and neg of the coil" doesn't really mean anything. Continuity between those two points is normal, but what you really want is resistance between those two, and continuity between others. Also, voltage readings from several areas would be very helpful. Do you have a meter?

If you do have a meter, one test you could do is to turn the key on and see if you have battery voltage at the negative post of the coil. Maybe you already did that and that's what you meant by continuity?

You really need to post a picture of the top of the coil and the ballast resistor all in one frame.

Excellent that's what I shall do tomorrow. The kit I ordered only came with the 4. That may be suspect. I have a meter. I get voltage on the negative and positive coil. I will take all the photos tomorrow. I had the battery terminals on correct the first time. They only extend so far.

Thank you Zed Head,