SteveJ

The FSM has wiring diagrams that include origin, destination and connector locations.

The old "pull the cable off of the battery" trick is overrated and not wise IMHO. Do you have a picture of the relay that was around the steering column? I don't recall a stock relay being there. Be sure to download a copy of the FSM. The BE section is invaluable for finding wiring issues. If you understand how to read it, you can locate most any electrical component easily. So many potential issues here...First thing is sounds like is that a PO jacked with the wiring. That can be difficult to diagnose & repair. Isolate all of the problems and investigate them individually. If I wasn't working too much, I would post more help.

Why are they "no good"? Pictures would help. Door panels do show up on eBay.

I think a bigger issue might be replacing the rubber parts in the fuel system to those that can tolerate a higher alcohol content. Isn't there a rubber diaphragm in the mechanical fuel pump?

First, inspect the ground wires around the steering column. After eliminating the ground as an issue, work your way though the different circuits one at a time with a voltmeter. Do that with the headlights off and on. I still think it's a bad ground somewhere.

See post #23 in this thread.

Eiji is also an active and respected member of the Z Car Club of Northern Virginia. Though I haven't purchased anything from him. I would if he had a part or service I needed.

Until I start reverting to my curmudgeonly attitude. Thanks for the compliment, Phil. Of course, in this case, an expert is someone who has made plenty of mistakes and has learned enough from them that the frequency of repeating said mistakes has dropped significantly.

To be perfectly clear, I didn't respond to that part of the thread. My earlier responses were that you had both internal and external regulators. The only time I ever had both regulators at play was about 11 years ago. I replaced the alternator in my 73 and while testing the addition of relays to the headlights, one of the headlights burned out. I checked the voltage at the battery with the car running. It was 17 VDC, so I quickly shut the car down and started researching the issue online. I quickly realized that I had an internally regulated alternator, so I followed directions online and jumpered out the circuit for the external regulator. I never at any time experimented with running the car with just the external regulator unplugged.

Yes. No. You can find out by measuring about 17 or 18 volts at the battery with the car running. Yes. We told you that before.

If the running lights are fine, then it is unlikely the combo switch. The gauge lights and running lights both come off of the green/white wire from the combo switch. It has to be downstream of that, either at a connector, the rheostat or the ground coming off of the rheostat.

Do your running lights come on? If not, it's a fuse, combo switch or connector. If the running lights come on, try the rheostat.

Rumors have been going around for a while...http://www.thedetroitbureau.com/2011/07/is-datsun-name-being-revived/

Well, the click you hear is the fuel pump relay. Hopefully I can have a chance to review the 73 wiring diagram and come up with some solutions for you. Don't expect any answers before you wake up on Saturday.

Suggestion - (Assuming this bolt isn't reverse threaded...) When you go to drill it out, use a left-handed drill bit. It may catch and turn the broken bolt, allowing it to come out.

I can't help you on oil pump selection. For searching, let Google do the walking. Use this text in the dialog box for the search on Google: "oil pump" site:classiczcars.com Here is what I got from that search.

Sorry, I was tired when I typed that last night. Green and yellow/blue are from the light. As I said yesterday the Y/L wire goes back to the sender. That is the negative side of the circuit. I haven't ever seen a 280Z sender to know how it is wired. However, I would guess that your problem is either that or a loose piece of metal is grounding out the negative contact on the light.

Well then, I think we may have found the source of your problem. Of course, this is how torque specs for an electrical engineer: Tighten as hard as you can. If the bolt breaks, you overtorqued the fastener. Now here is a little known fact about electricity. Many people assert that electricity is the flow of electrons. It is not. It is the flow of magic smoke. The smoke travels in the wire. When you let out the magic smoke, there is no more electricity to flow.

Check around the fuel pump sender. According to the wiring diagram, there are two wires. One is green (power from the dash lights circuit), and the other is yellow/blue. The Y/L wire goes back to the sender.

The advantage of the internally regulated alternator is that it has a higher output.

I have one for each of my Zs, but I haven't installed them, yet.

It most likely doesn't matter. The Wesco belt retractor doesn't sit in the pocket.

I agree with Leon. Start with the grounds around the steering column. Also, find a copy of the wiring diagram. Look for any black wires (with no stripes). They are marked with just a B in the wiring diagram. One or more have lost contact with a component or with the chasis.

Go to Zhome.com and look at the link on inspecting a Z car before buying it. The pictures you show don't give much detail, especially with regard to the rust-prone areas. My philosphy is get the best body car you can afford. You can always get a new drivetrain.