SteveJ

You may consider changing out your old electromechanical flasher relay with an electronic relay like this: https://www.amazon.com/gp/product/B0811GTVH2/ It has a speed adjustment that I like. The thing is that you'll have to run a ground wire to it to make it work.

I think we could make a meme of that, Alan.

Are you familiar with George Washington's axe? Someone is selling George Washington's original axe. The handle has only been replaced 5 times, and the head only 3 times. So I guess if you took the original East African Safari winner, replaced every single part & converted it to left hand drive, the video could have been using the original.

I never had tach issues with ZX ignition in my 260Z. (Same general design as the 280Z tachometer circuit.) It was modified by a PO. I eventually bypassed the ballast resistor and using a coil with similar impedance as a 280ZX coil with an E12-80 module. No problems. I'm not sure what you mean with respect to adding a resistor in addition to the one that's in the circuit.

Has your fuel pressure decreased causing a lean condition? Lean=hot

Start with the wiring diagram from the FSM: It shows one wire coming from the fuse box: blue. There is another wire coming from the resistor: blue/white. The wiring diagram shows this as yellow/white. Finally there is a ground wire. From this approach, the first thing to check is quality of the ground. Measure resistance to ground on connector on the dash harness side at the black wire. Also make sure there is no resistance from the connector on the gauge to the gauge body. Clean the connector with Caig Deoxit while you're at it. Next, as I stated before, check the resistance from the blue/white (or yellow/white) wire at the dash connector to the negative post of the coil. You may need to make an extended lead with an alligator clip to reach. You can build your own probe with something like this: https://www.amazon.com/Insulated-Multimeter-Stackable-Connectors-Adapters/dp/B07C535GBD. Also make sure the dash to engine harness connectors are clean.

Was that with the key in ON? If so, move to the other tests. If not, re-test with the key in ON. What we are trying to figure out is why you're not seeing voltage to the relay that completes the circuit for the solenoid. If we don't find voltage on the downstream side of the ignition relay, we need to test to see if you have voltage going into the ignition relay. After finding faulty components, we can replace just those components. The goal of this is to fix with spending the least amount in replacement parts. Did I understand that you replaced the ignition relay? If so, where did you get the replacement?

The junction between the dash harness and engine harness is in the passenger footwell. C4 is a white connector. You want to work your probe in on the back of the connector so you can measure voltage while it is connected. It should be at the block marked 3 in the picture, though many people have removed that junction block, especially if they installed aftermarket AC.

Thank you for the feedback. So the inhibitor switch may not be the immediate problem, but we haven't ruled it out. Have you checked for voltage to ground on the white/black wire at connector C4 with the key in ON? Also check for voltage to ground on the black/white wire with the key in START.

You may have missed my other reply. Try starting the car in neutral and report back to us.

Trace the power for the coil on the relay at the top of the image you clipped. The white/black wire comes from the inhibit switch on the transmission, and if you trace the white/black on the other side of the inhibit switch, you'll find it goes back to the ignition relay. The OP has an automatic. He has posted on starting issues before.

I'm curious. Have you tried to start the car with it in neutral? Recently a friend with a black/gold 10AE said his starter gave out. I told him that before he orders a starter, he should verify he had voltage at the solenoid. He measured and said he had no voltage there. I went to his house with a remote starter. I verified his reading and used the remote starter to start his car. After consulting the wiring diagram, I traced it back to an ignition relay and verified the coil was not getting power. That led me to suspect the inhibit switch on the transmission. I told him to put the car in neutral and try starting. It started right up. I don't recall seeing anything in this thread about trying to start in neutral. Try it and report back.

Typically the condenser suppresses noise with the rapid changes in the magnetic field of the coil. Interestingly enough, the 260Z does not have a condenser in the wiring diagram for the ignition. I'm not sure why. The 1980 has the condenser on the positive side of the coil (E12-80 ignition module). My thought is that if the resistance is too high between the ignition module and tachometer, your tachometer isn't getting the signal it needs to react. Also, if the blue wire for the TIU is coming into contact with another wire (or is connected to the TIU still), that could affect the signal quality going to the tachometer. We know the blue wire for the TIU isn't solidly grounded, otherwise your car wouldn't start/run. A few years ago, a friend brought over a customer's 260Z that wasn't running that well after a ZX distributor swap. I don't recall if he said whether or not there were tach issues. The first question I asked was, "Did you disconnect the TIU?" After a Homer Simpson "D'OH!" he disconnected the TIU, and all was good. You may consider adding a meter like this to your arsenal: https://www.amazon.com/gp/product/B0002LZU7K Among other features, it has a tachometer. That can make for better troubleshooting and analysis, not only for this problem, but for tuning issues, too.

I guess you'll find out how much is true and how much is stuff I made up. 😁

First, the condenser should be on the positive side of the coil. Do you still have the ballast resistor in the circuit, or have you jumpered that out? Next, measure the resistance from the negative post of the coil to the tachometer connector blue wire. It should be around 2.2k Ohms or so. Also, is the TIU disconnected? Is the blue wire at the TIU interface taped off so it cannot come into contact with anything?

I pulled that from @Terrapin Z's post. 28590-P7500 is not a valid part number, either.

I couldn't get 22590-P7900 to pull up as a valid part number at any of the regular sites that I use to find parts or validate part numbers. (I was not using Nissan FAST.)

https://www.ebay.com/itm/284463031696 http://zparts.com/?product_make=1980

That could do it. Depending upon how they modified the wiring, it could be a challenge to keep it working if you unplugged a few connections and are trying to reconnect everything.

Have you read through this? https://fiddlingwithzcars.wordpress.com/2013/01/20/hazard-switch-brake-light-turn-signal-circuit-analysis/

NOW I can talk about riding in the new Nissan Z. During the Mitty, I reached out to Rick Goolsby from HSR to see if I could get a ride in the Nissan Z pace car for parade laps. He said that Sunday was available, but I had to be in the gathering area at 10:45. I think I was there at least 15 minutes early. Jason, the driver, showed up with the pace car, and several of us looked around the car. The Nissan Z looks great in blue, and I have a feeling it will be a popular color. The car was a nine-speed automatic Performance model. A big motivation for me to get a ride was to see how tolerable the car might be for a daily driver. Even with my less than svelte figure and knees that barely function, I didn't have much of any issue getting into and out of the car. Since we were doing parade laps and not pacing the start of one of the races, the speed was probably slower, but we did five laps around Road Atlanta. What I really appreciated was how quiet the car is. My current daily driver is a 2012 Mustang V6 Premium. The interior sound level to me was closer to a Camry than the Mustang. If you are wanting to hear a rip-roaring exhaust note, you might be disappointed. I have a 260Z with a loud exhaust note when I want to experience that. If you're looking for a sporty, quiet daily driver that you can rip around the track or mountain roads, I think this will fit the bill. I enjoyed going through the Esses at Road Atlanta, and Jason was driving in a spirited enough manner that the gimbal on my camera was frequently trying to adapt to the G loads. We topped out at freeway speeds on the back stretch of the track. The ride was good, and I could see taking the new Z on a long drive without feeling like I was turned into a pretzel by the end. It wasn't going to take a lot to convince me that I really wanted the new Z. I think the styling is a significant improvement over the 370Z. The ergonomics of the car felt good when I sat behind the wheel of the manual transmission version. The only things that could keep me from buying one in the next couple of years would be ridiculous dealer markups or quality issues with the car. I still need to edit the video I took inside the car. I just have to make the time to do the editing.

My other thought is "Do we have to start another GoFundMe for their bail?"

Oh dear, they made the news again?

And @Randalla's version works well, too.

The hazard switch can affect the turn signals, but it's less likely in this case since the hazards work. Just double check that the connectors are plugged in firmly on the hazard switch. As for wire colors, use them to find the wires on the dash harness/engine harness/body harness. Connectors should only be able to connect one way, so if a supplier did not follow the right convention, the wire should still go to the right spot. The BE section of the FSM has good (but not great) documentation of what wire goes to what pin on the connectors.