I've been having problems with my 240sx's electrical systems, this morning was the latest incident so i'm posting for some help. When i get in the car the door lights and everything cut on, and when the key is in the ignition to acc everything is fine, but when i go to turn over the motor everything electrical dies and won't come back on, so i go under my hood and wiggle the terminal leads. I have recently changed batteries due to excessive corrosion because lack of a propper ground (it got corroded off, go figure), so i grounded the engine to a shock tower, and then ran another lead from another bolt on the shock tower to the negative battery terminal. There is some white corrosion on the bottom of the negative terminal clamp, but not as bad as it used to be and the positive side is fine. Any ideas what could be wrong? (and no i won't be buying anyone dinner for help )

John

 

so after you wiggle, does stuff come back on? Are the wires that go to the positive terminal of the battery (smaller wires) ok? Make sure the signal wire to the starter isnt jumping to ground or something.

My S13 had some crazy *** electrical problems. Ended up replacing the engine and dash harnesses, still weird. My ECU would stay on, even with the key out. crazy.

Edit: PS. waht does your miata look like just so I know if I see you or not around town.

 

This same thing was happening to my IS300 and it was caused by the negative battery terminal.

 

Clean the battery terminals and leads, spray anticorrosion spray on them and the leads, then put those 1 dollar red and green corrosion protectors on battery, then reinstall terminals and tighten them so that you can NOT wiggle them.

I use baking soda paste to clean the terminals when they are really bad.

 

patsmx5 advice is all good, my ranger wouldn't start, the battery terminals had zero corrosion that you could see. I took the neg terminal off and sandpapered it up to get it all clean, applied some dielectric grease for good measure and it fired right up. Haven't had a problem since. Clean your batteries of all corrosion and then apply protectant ALWAYS.
Even if it is just a 240.

 

alright then I'll do all of the above for good measure, even if it is just a 240 then i'll post back with success or failure, thanks!!

SloS13:
I'm rollin around in my blue 240 hatch right now, its easy to notice as it has first gen 300zx wheels and the headlights are always up (and windows always down no a/c), i've been looking for IC'd miatae around but the only one i thought i saw was a MK2 with a taped together top

 

Dont think I've seen a S13 with Z31 wheels. I live near garners ferry and work downtown. Sometimes I go to bush river road for lunch. At night im driving around tuning on my laptop pulling my hair out.