I had a problem with a very rapid drain on my battery a few weeks ago on my 280. with the help of everyone here I managed to narrow it down to the voltage regulator. So, I tested it, and ended up having to replace it. Did so. Now for the current problem:

I replaced the voltage regulator 4 days ago, the car ran fine, no problems. I kept the battery hooked up to see if the new regulator would do its job, and it did. So for 3 days my car would start up with the first turn of the key, no problems. Now, on the morning of the 4th day, totally dead. I went to start it up and nothing, not a turn over, not a clicking, nothing...just deadness. I checked and rechecked the connection on the voltage regulator. I also put a meter on the battery and its completely dead. Im at a loss of ideas right now. For now Im just going to see what I can see and try to figure it out, but any help or suggestions are always appreciated. I might need a little help on this one.

Thank you in advance everyone,

John

Funny, I had a similar thing happen on my '73 and now am a bit afraid to drive it for fear I will get stranded. Aside from the voltage regulator, which I would like to replace, my guess was that the problem on my car was the battery hold down bracket. It seems a little too close to the terminals and I am thinking something may have shifted while going around a curve. I will monitor and keep posted.

Thank you, I'll check that out on my car as well!

Just tested the alternator.....she bad.

Get the 280ZX 70 Watt Alternator for an internal regulator! If you don't care about originality so much... Much worth it.

FYI, common wisdom (for whatever that's worth) usually says to replace the regulator & alternator as a pair. I didn't do that in my 73 when the regulator went south, but apparently a lot of people see the two die as a set.