Car will power up but won't start sometimes. But then I go out later in the day and it will start. More common when it cold out like 32 or below. And now a new ripple the battery is dead every morning. I jump it and it stays running and will start up after it runs for a min. But if it sits overnight dead in the morning. Only 1 time when I put it in neutral did it start other times no. I spent 2000 having the pdmi replaced that wasn't it (dealer diagnosed it) took back then replaced neg batt cable.
Batt is good only a year old. Alternator replaced last summer. I'm at a loss anyone have this problem?

First, sounds like a weak battery. Chronic over- or under-charging can wreck one in far less than a year, so it isn't fair to assume it's good. The M's all have the Nissan "smart charging" setup which can go stupid from any number of small issues, from bad grounds to a bad battery current sensor. On an old ride the best solution is to bypass it. There's a whole 5-page thread in here about the problem and the solution, which is actually very easy:
howto-disable-ecm-controlled-alternator ... 6-120.html

Second, "won't start" is a nebulous description which doesn't provide enough info to be helpful. Does it cycle on-off without cranking when you press the button? Does it crank but not light off? Does it make one loud click, or a bevy of small ones? Do the lights dim or go out when it tries to crank?

when i get in car i push on the brake and hit start button. all lights come on as normal but wont start. not a click or anything. if i come out later in the day it usually will start after that. only once when i tried to put in neutral did it start in the morning. light don't dim it turns on and off just fine. doesnt make any sounds when i push to start. i notice it only does this when it really cold out. it did it a couple of times after a super hard rain. i know chrysler was having problems with relays sticking when it was cold out (was told this by a company that programs cars at my shop). i had dealership replace pdmi module still does it. then they replaced neg cable on batt still does it. dealership expensive. I also read that there is a box on steering column that you can tap because a plunger might be sticking. so then i went outside to try and batt dead... so new problem.

when dead if I jump it and it actually starts then it will run fine. i can turn off and it will start up again. not sure what is draining the batt. dealership looked at it and cant find anything... i do autobody not a mechanic lol. it is a nice car i would like to keep for my daughter but want it reliable. i watched video it said something about brown wire to remove on the m56. i tried looking for a wire diagram so i know the color of wire but cant find it or just dont know what im looking for.

thanks, dave

If the key cycles off again with a second press then your brake pedal switch is causing the no-crank issue. I'd still get the battery checked, it could be weakened from chronic undercharging and simply won't give you enough CCA when cold. You can find the diagram for your charging system on SC-21 here, the Yellow wire on pin 33 of the IPDM is the one you want to cut and cap:
https://www.nicoclub.com/service-manual ... 8%2FSC.pdf

Thank ypu I appreciate your help. I will.try these out next couple days. I'll post what happens