SteveJ

Where in the dash harness did you find the wires? What other connectors are nearby? Location can help narrow down function. Edit: By the way, a quick look at the 71 wiring diagram tells me that instrument lighting is the purpose.

At one time I posted what wires need to be jumpered on the seatbelt interlock to defeat it. Search through the archives to find it.

Not too surprising for a northern car. There was a guy who posted at Zcar.com that went by Matteo. He bought a Z from Chicago, and it had plenty of tin worm and fiberglass. He restored the metal on his. Search for his posts over there.

Glenn, Thanks for elaborating. It helps a lot. The tach and gauges are on completely separate circuits. As Leon suggested, there could be issues with connectors, quite possibly the dash connectors. If the car is running fine otherwise, it reduces (but doesn't eliminate) the chances of a failing fusible link. The FSM does break out the circuits in the BE section to make it a little easier than just following the wiring diagram, but you will still need to look at the wiring diagram from time to time. Of course, the troubleshooting section of the FSM does suggest something interesting. A bad voltage regulator could affect your gauges. The EE section tells you how to test the voltage regulator. The FSM is your friend and can give you better advice on fixing your problems than many of us.

It could also be the seatbelt interlock relay. As Leon suggested, the information is available. You'll just have to do some sifting to find it.

Glass fuse going bad, corrosion in connectors, hacked wiring, fusible link, full moon...You don't give us much to go on. When exactly are they going out? Your description is a little confusing, too. Are the gauges malfunctioning, or is it the lights for those gauges? Have you had other electrical issues? Have you checked the voltage of your battery with the car running to see if the alternator & regulator are working properly? Overvoltage conditions can cause issues, too.

You're now officially Ron. We'll also periodically change your name to keep you confused. No one that I know of is manufacturing reproduction harnesses. You could try to adapt a Painless kit or get a used harness from Z Car Soure, Zbarn or Z Specialties. Don't expect used wiring harnesses to be perfect or cheap. You can get many different types of replacement connectors from Vintage Connection. When getting a used wiring harness, try to get one from a car with a similar build date to yours. If the wiring harness has a part number, contact Mike to buy a CD of the parts manual to find the part number appropriate for your car. If I was given a choice between 3 Z cars, one with a bad body, one with a bad motor, and the third with bad wiring, I'd probably take the one with the bad motor. I'm not even that good with engines, either.

It's difficult to say. What is your goal? One of the best ways not to waste your money is to know what you're trying to achieve and why you're trying to achieve it. However, we're moving away from the purpose of this thread. I suggest you start a new thread in the appropriate section to ask suspension questions.

Okay, so you're near Attalla.

He's probably not near a Harbor Freight unless he's near Huntsville or Chattanooga...

For whatever reason, the driver's side door panel for a 74-76 is a very rare item indeed. Roger may not be back in the swing of things after the loss of his wife. Meanwhile, keep searching eBay. They do show up from time to time.

280Z springs aren't a good choice for the 240Z.

They will fit provided the 280Z wasn't a 2+2 or wasn't actually a 280ZX. I've heard a couple of stories about guys getting burned each of those ways.

Not too long ago, I checked my plugs and found they were fouled. Following my own advice, I read through the FSM and came across the diagram Phil posted. I was in a hurry and just did minor adjustments, using my ears as a crude tuning tool. I leaned out the carburetors a little and bumped up the fast idle to keep the engine at a nice idle speed. The end result was that the car behaved better, and the plugs didn't foul. To me, it was just as easy as working with the SUs. I didn't think Tony was yanking our collective chains when he said there was something to the flat tops. I just hope I can open my mind up enough to understand.

Phil, I don't have a pair to spare, but I do have a single flattop sitting on my garage floor, ready to give its life in the name of learning. If you want it, send me a PM.

Okay, I can see the pictures now. Of course, I need to get a lot smarter about carburetors to really understand the post.

Unfortunately, at the time I am viewing this, there are no pictures.

Well, the name of the file is jet. Would you be so obvious?

Arne is correct. The battery still feeds on the positive side of the ammeter, and the alternator feeds on the negative side of the ammeter. Taking out the ammeter will more than likely kill all of the circuits fed by the large white/red wire. There is a test to verify this. Take out the ammeter and turn the key to Start. If the solenoid engages, then Arne and I are wrong. Given that fact. Jim, here are some more diagnostics for you. (See this description of the alternator mod for more information on where the wires land.) 1. As I stated before, if you do not see a voltage of at least 14 volts at the battery with the car around 2000 to 2500 RPM (It should be more along the lines of 14.5 or so.), then the battery is not charging. 2. With the car off, you should be able to check the wire for full-field bypass. Measure at the yellow wire at the alternator to ground. You should have 12VDC. 3. Next check the ignition signal. Put the key in the RUN position. If you measure voltage from the white/black wire at the alternator to ground, you should have 12VDC. If you don't have charging while the other tests pass, your alternator is bad. If either tests 2 or 3 fail, you have wiring issues.

Jim, no, you shouldn't remove the adapter. While the voltage measurement is a quick & dirty check, it doesn't replace the diagnostics in the FSM. Those diagnostics will help you pinpoint the problem. Chris, if the alternator is putting out less than 13.2 volts with the engine at speed, there is a problem with the wiring or with the alternator. Again, the FSM diagnostics will pinpoint the problem. Oh, and by the way, the FSM for a 78 280Z or for a 280ZX will have diagnostics to help pinpoint the problem.

Jim, You can always download a copy of the 78 280Z FSM or any 280ZX FSM from XenonS30 or XenonS130. From there, you can see the alternator diagnostics. Another way to check is to take a voltage measurement at the battery with the car off. It should be between 12 & 13 volts with a good battery. Have a buddy start the car and hold the throttle to between 2000 & 2500 RPM. Take another voltage reading. It should be between 14 & 15 volts. To be perfectly clear, jumper out the external regulator BEFORE doing this test. This test is just off the top of my head, but the FSM will give you solid diagnostics. As for the voltage for the temperature sensor, detach the wire from the sensor, and measure from the wire to ground. The key should be in the ON/RUN position. The engine does not have to be running, but it won't hurt if it is running. The key position is what is important. You have to have voltage going through the gauge. By the way, has the oil pressure gauge been working? Those gauges have a common 12VDC+ coming in.

Darn, I thought I responded to this last night. If Enrique is correct that you have an internally regulated alternator paired with an external voltage regulator, then you should be able to detect that with a voltmeter at the battery with the car running. Unfortunately it's easy to detect because you'll have an overvoltage situation that can do VERY bad things to your electrical system. Also note that jumpering out the voltage regulator won't necessarily resolve the issue with the car not shutting off. You will need a diode in the alternator circuit when you use an internally regulated alternator to prevent it from feeding back through the ignition. For the temperature gauge, the sensor itself is the load in the circuit. You should be able to read voltage between the sensor wire and ground when wire is unplugged. It's good to verify that you have a signal first.

You could also try a brass hammer.

E, I misread part of his post. I thought he said he cleaned the sockets. Part of the problem is that the wire is on the small side for the current load going through it. IMHO the fuse should be 10A instead of 20A. That would better protect the wire. Yes, corrosion will make current draw worse since the corrosion can create a short circuit when it becomes so extensive that it breeches the gap between the positive contact and ground. However, from his description he chose to implement unique engineering solutions into a car where a previous owner apparently went to town already on the wiring. I would agree that the best way to test the system would be to take current reading on all branches, provided the wiring hasn't been hacked to a point where there are unknown parallel branches causing the overload. Most people (and I'm sorry if I offend Ron by including him in this group) don't know much about current measurements. It doesn't seem like he followed my earlier diagnostics that would have required the use of an Ohmmeter to track down his short. Having been victimized by the parking light circuit in both of my cars, I decided that the best course of action for myself would be to clean the sockets and substitute LED bulbs. I mentioned the parking light relay harness because it will give Ron the time to diagnose further without burning up his fusebox. Unfortuntately it sounds like he is close to burning it up already.

That is not an usual circuit to have problems. Go to Motorsport Auto and order the parking light relay kit. It was designed and built by Dave Irwin, aka Zs-ondabrain on this website. To see why parallel circuits would increase the current through the fuse, look at this example.