Ok heres the story.1990 300z,wifes car,Kills battery after 3 days of sitting.I put a test light on the neg.battery and clip to the neg wire. Light shines bright.I disconnect the small pos.cable that runs the car electrics. No change.The large pos goes straight to the soleniod.I unhook the starter from the soleniod.No change.I discon. the large wire from the solenoid.Problem gone.Check the solenoid for ANY problem,loose post,hairline cracks, continuity,All is well.Run a jumper from large cable starter end to soleniod.No problem.Perhaps its the nut tightening on the solenoid post that is the trouble.NO.Why is it the cable must be attached for the demon to appear???When it is attached it is touching NOTHING!!!but what it should.I put two flat washers on the solenoid post before attaching the cable.NO PROBLEM!!!It was a fluke I say.Remove the washers ,Problem,put them back No problem.The car has never been touched there.EVER.I know sometimes you just don't ask why but damn!!!

I often find the answer is the most obvious that I haven't even considered, can't give you an explanation myself just felt someone should reply to you and feel pity for ya .

Could the washers be helping the contact in anyway?

Daniel,

I might be right off the track but from here it sounds like a fault in the wire terminal end fitting. Could it be that you have corrosion inside the terminal when you remove the washers it loads up and looses contact (maybe the terminal has been catching water).

just a thought

Steve:classic:

So the battery draining issue was fixed.I am a "must know "kinda person,but that will remain a mystery.New gotcha.In my search for the battery problem I found a "cheater" type connector that attaches to one leg of a fuse.It was to power a cell phone that is no longer used.This car has the plastic modern fuses not the glass 313 type like a 240.Last night I go to turn on the lights.No dash lights or tail lights.I wiggle the fuse and I hear relays clicking.I thought of bending the fuse legs to compensate but didn't want a "custom" fuse.Put the cheater back on and all is well. Moral of the story is once you use one of those cheaters it spreads out the connector and you are stuck with it.BOY!! they took all the fun out of working on a Z when they built that 300ZX.