SteveJ

I haven't been neglecting the 240Z for the past week. I have just been waiting on finishing things before posting about them. Early in the week I purchased a premium $20 Dual brand receiver from Walmart to install in the car. No CD, no tape deck, but it has USB, Aux, and Bluetooth. I wrestled out the old Audiovox tape deck and shook my head on how I wired it 28 years ago. The only good thing was that it was an excellent benchmark to show how far I have progressed over that timeframe with regard to my wiring skills. One of the challenges was finding a source for the constant 12VDC source. A long time ago, I jury-rigged getting the power from the map light. Yeah, that wasn't happening twice. Using the FSM wiring diagram and my multimeter I figured out my solution. The 12VDC switched source would be coming from the 3 wire connector for the radio. The ground would come from the 3 wire connector for the rear defrost switch. The 12VDC constant would come from the rear defrost relay. I made jumper harnesses for the ground and 12VDC constant. I connected everything and tested the stereo. It worked...except for the right front speaker. I tested the wiring, and found the positive wire was broken somewhere. I decided to start looking at how to install the speaker enclosures. Early on I discovered the old speakers were too deep. Fortunately I had to source speakers for the 260Z to fit the enclosures, so all I had to do was order another set of Pyle speakers from Amazon. Again, nothing but top shelf stereo equipment for me. After the speakers arrived, I put the stereo end of the speaker wires into a connector. I also started fitting the enclosures. I had to trim the driver's side to clear the dead pedal. I also had to get some longer M6 bolts for the hood release bracket, but I plugged the wires into the speaker and got the enclosure mounted. Then I went to work on the passenger side. I decided to remove the fuel pump relays since they are not being used any more, and I removed the relay bracket. I did dry fit of the enclosure and trimmed it to go in more easily. After plugging in the speaker I went to install the relay bracket...Well, that took a lot longer than I hoped. It doesn't line up that great, especially with regard to the top bolt when you have the lower bolts cinched down. It doesn't help that you can't see how misaligned thing are unless you can miniaturize yourself and contort your body just right. Anyway, after an hour or so, I finally got the bracket mounted. I plugged in the stereo and tested. Yes, I have tunes for my next road trip. After I was happy with the stereo install, I pivoted to the hazard switch. I got the retaining ring loose and pulled the old switch through the dash. The connectors came apart with a little coaxing. I dug out the replacement switch that I found despite buying it 16 years (and one move) ago. I got the wife to direct me while I tried to line up the switch with the opening in the dash. That's another thing that took a LOT longer than I remember it requiring. UGH! I managed to get the retaining ring on without pushing the switch back through the dash. After installing the knob, it was time to test. The turn signals worked. Now for the hazards...Nothing. Dang it! Fortunately I knew where to look. It was my own blog where I broke down the turn signal circuit. I saw that the white wire from the battery fed the circuit. I checked for continuity between the wire at the dash harness/engine harness junction and the fuse box. No continuity. Dang it! After dinner I removed the center console. I also pulled the stereo. I removed the screws holding down the fuse box so I could pull it toward me for examination. It took about all of 5 seconds to find a connection that pulled loose. I got it reconnected and buttoned up everything. I LOVE removing/replacing stuff for about an hour to work on something for 5 seconds. Anyway, I tested again, and all worked fine. I found the bulbs loose on the tachometer, so I got them plugged in for the turn signal indicators. I tested the horn again. Well, it almost makes noise...I figured it might be time for a new relay. Who knows? I might need to clean or replace the horns. I sat down and ordered a bunch of LED bulbs and looked for a horn relay on RockAuto, Z Car Depot, and MSA. No one has a friggin' horn relay anymore. When the hell did that happen? I found a generic horn relay on ebay and ordered it.

My research corresponds to what @CanTechZfound.

They are trying for Barber. Talledega Grand Prix is the backup plan. I can tell you that getting the track commitment is one of the most difficult parts of organizing the event. The next most difficult is finding an appropriate locations for the car shows. For instance, for 2018, we approached Chateau Elan for the judged car show (and convention hotel), and they basically said, "Oh Hell F'n NO!" Fortunately for us, Z1 Motorsports had relationships with Road Atlanta and the venue for the People's Choice shows. Anyway, I hope to see a lot of you guys in B'ham.

That settles it. We'll establish the CZC base camp at Cliff's place. 😉

And I heard from a friend who is at ZCON it might be in October. I'm in either way.

Dang it. I posted this first in the 510 Open Discussions. The rumor mill was right. ZCON 2022 will be in September in Birmingham, AL. I hope I'll be paying more attention when I'm prepping my Z than I did in selecting the forum...

See the Z Open Discussions for my post on ZCON 2022.

The only way to get to the drain plug is underneath. The easiest way to remove the fill plug is underneath. NEVER attempt to drain the transmission without first verifying you can open the fill plug. Yes, you could fill at the reverse switch, but that is a pain, and again, you have to be under the car to get to that.

Well that's interesting. It appears as though the 73 (my car) has a slightly different grille as the mounting tabs on my car clearly bend up. And...the parts catalog bears that out: 62300-E4601 is for the 70-72 and 62300-N3301 is for the 73. The different grille accommodated the 73's bumper mounts.

As @Terrapin Z said, the tab for the lower mount needs to be turned up. Look at about 1:09 in the video. Here's a closer photo, but the wiring for the headlights obscures it a little.

Make it a 6 pack of Diet Dew. I don't drink alcohol like normal people.

I have a feeling that it's wear on the contacts on the ignition switch allowing bleed over somehow. Maybe I'll run a test at the switch some day.

Oh, so you want a video? Now I'll have to charge you.

I did some testing with the wires swapped. While there should not be voltage at the coil while starting with the wires swapped, I did read a little over nine volts. That may be from slop in the contacts with a switch that is almost 50 years old. I also pulled the negative off of the battery and checked resistance between the black/white for ignition and the positive post of the battery. At first it was just a couple of ohms with the key in ON and about 50 ohms with the key in START. However, I noticed some fluctuation in the readings with the resistance with the key in ON increasing when I released the key from START. That is why I think there could be some slop in the switch. However, I was not seeing any continuity between the black/white wires no matter what position the key was in. I'll test some more later.

That is called a hinge. I can take some photos later today.

I will verify this evening. It will only take a few seconds with a meter. I still have my doubts about being able to start the car with the black/white wires swapped.

Yes, I have my doubts about the swapping of the wires. I'll have to test that this weekend. Anyway, I believe the OP has his car wired correctly, so I hope he didn't swap wires.

It's one of the most rust-free cars you'll find outside of the southwest US, but the frame rails have been beaten up completely from idiots using them as jacking points. The funny thing is that I set the valve lash, changed the oil and balanced the carburetors before the seller bought the car. And I got advice on setting the carbs at high RPM from the person the seller hired to set the valve lash, change the oil and balance the carburetors. The only thing he didn't mention is setting the dwell, which I did as well.

Here is one that personally worked on. I know the seller and previous owner. https://bringatrailer.com/listing/1971-datsun-240z-179/

When you did the continuity measurement, was the tach plugged in?

You missed a key detail in my video. I said ALL the wires were disconnected. You had the ignition wire connected to the ballast resistor along with the green/white wire. That's why you had voltage on the black/white at coil positive. Anyway, all the wires are connected properly. Post a photo of the back of the tach if it's still out. Let's make sure it's a 240Z tach. It would take some rewiring to mate a later tach to a 240Z, but with the other surprises on your car, we don't know what we're going to find.

You are correct about it not looking stock. It looks more like a 260Z housing. (I just went down to the garage to look.) For reference my 73 does not have that fitting, but my 74 does. @Captain Obviousmay have the size memorized. It could be a BSP fitting. Anyway, the fitting is for the water temperature switch for the 260Z EGR control. If you are really curious, see page EC-16 in the 74 FSM. The switch is still on my 74, doing nothing. When I needed to install a coolant temp sensor for the fuel injection I put on that car, I used the fitting on the side marked below. It's 1/2inch BSP. I found the right size BSP to NPT adapter for the coolant temp sensor. The 74 already had the coolant hoses removed from the carburetors. I plan to remove the coolant hoses from my 73 soon. I just have a BSPP plug for the side fitting. I bought an elbow fitting from Napa to replace the three-way coolant pipe on the passenger side of the block.

Load test the battery to make sure it is good. Make sure the battery is fully charged. Download the FSM if you don't already have a copy. Focus on the EE section. Use an ammeter (not the gauge) to look for any drains on the battery. Hint: unplug the voltage regulator to see if that kills a drain. Test the charging system components, using the FSM as a guide. Make sure you are making notes on what & how you test with the readings/results so you can share with us along with details of what you have worked on/modified. If you're not sure of how the charging system works, then I would advise against modifying the wiring. Especially with the 260Z, if you don't know what you're doing, you'll quickly wind up with a car that does not start.

It could be the voltage regulator. Also, make sure you charge the battery fully. Running the car with a battery that is too weak/low can damage the alternator. Do you know how to use a voltmeter? You may also need to use an ammeter. This type can be helpful if you learn how to use it. https://www.amazon.com/Current-Auto-Ranging-Digital-Ammeter-V-Alert/dp/B094R8CB4W Until you can take some measurements and diagnose, you're just throwing parts at the problem. While you may be able to solve it that way, it tends to be more expensive. Also, following what @Zed Headsaid, go to Account Settings (Click on the dropdown at your username if you're using a computer to access this site.) and then go to Signature. Put your car information in the signature. That will help people know what car you are working on. There are wiring differences between the years.