EDIT sorry if original post was not specific enough to allow for remote diagnostics. Following is a short list of my personal findings/musings/theories/questions(!) on the matter of aforementioned 1984 Datsun (according to the title) Nissan (according to the badge) z31 NA 2+0. THank you if you read the original post, if you feel like sharing anything at all I will be happy to run any tests if necessary, not sure where to start as I fear I may have crosssed over into the territory the FSM calls "REPAIR WIRE HARNESS" with regards to most of the issues ive encountered, components that do not work, and overall startability. heres the long story medium length (best i can do):

PO became incarcerated, car was sitting for some time on side of road. multiple would be new owners (or thieves as I like to call them), believing themselves to posses such levels of "general across the board automotive experience" that they might attempt top start and drive said z31 from the spot it was parked at, WITHOUT CONSULTING ANY REFERENCE FROM THE LOOKS OF IT! and I should add a were likely motivated purely by their own personal lack of motor vehicles fort obvious and probably reasonable reasons. SO i told my friend the state of his z and he promptly had me help his mom break intro his safe and retrieve the the title, armed with nothing but said title (a formidable foe indeed to those who run in some circles within which, the automotive title is only ever seen as a poor forgery or discussed as mythical subject matter perhaps real in the days of yore but certainly no more..) was able to (just in the nick of time, i might add) assert my claim of ownership in the hours before it was to be sold for petty cash (<500 i believe). Even if it never runs, it is a symbol of symbolic victory for the home team and those are rare but truth be told we do want it to run. it deserves to run. all interior parts were in the back hatch along with almost mint condition dash and floor carpeting out of an 89. swapped the dashes and the harnesses. by the way I HAVE A FULLY INTACT AND FUNCTIONAL DIGITAL DASH COMPLETE WITH POWER UNIT AND DIGITAL COMPASS AND BOOST GUAGE that I would be willing to sell or trade for some parts my car needs. also have the completely intact WIRING HARNESS! I personally stuck with the needle type meter because the '84 lacked the speed sensors and compass etc. that make the light show happen in the first place.

OK BACK ON TRACK HERE WITH MY PERSONAL THEORY #1) Fusible link box was not hooked up when i got the car back. splicing of wires to ECCU and removal of battery wires to the interior of vehicle by would be thieves to deter other would be thieves leads me to believe I may be missing some obvious wiring solutions. there is no continuity to ground between the positive side and negative side of 3 fusible links. all of them have 12v if I ground them directly to the frame, but if i try to do it through the harness, nothing.

could this be the cause of the low voltage reading inside the car? or could the voltmeter be broken? which brings me to theory #2..

THEORY #2 (WISHFUL THINKING?) voltmeter is in need of replacement, I don't have any evidence to support this theory but it sure would be an easy remedy!

that being said, I'm going to sign off for now. ill return later with pictures,m assuming this migraine relents.

Hello Zdriver, been reading this forum for a while and thanks for the useful info. on here (w/o which i might have made an account sooner!)

I have a 1984 z31 I have been working on and I have been unable to start it due to a nagging electrical issue: Battery reads 12V inside the vehicle voltmeter reads 8V. is there something painfully obvious I should consider before undoing any of the alterations to the E.C.C.U.'s wiring courtesy of previous owner(s) "unknown"?

E.C.C.U. currently displaying Code(s) 23 +31

Took my time hooking up the battery cables and reference the FSM often, checking multiple times for errors as I Was hoping this would be the source of the issue. Supplemented direct GRND. to battery due to some rust on pretty much every part of the frame, from the E.C.C.U. I read about a method called a star ground on here, I think, if this is a good idea could someone give me any tips before I begin? I hate redoing electrical work and always try and skip straight to the solder. Only effective if you get it right the first time, which I clearly have not.

Thanks for your time & have a nice evening!