2001 LX470 no crank when cold, Only when Warmer than 40f

[medtro]

What is also strange... when running off the aux battery in the trunk ( main battery disconnected) above 40 degrees with just 9volts the car would turn over and start... I am so lost.

Move the main battery to aux battery tray to see if you have the same problem. This should narrow down the problem area.

I think there is something else going on if you were able to start with 9V.

 

[LXFAM]

Randomly deciding to close the loop and reply back to my own thread. This ended up being a faulty neutral safety switch. It just happened to fail pretty consistently when temperatures dropped, and only after it sat for more than a few hours.

I lit a camp stove, slid it under the transmission where the neutral safety switch was. Ran into the cabin and it turned over without an issue.
This drove me CRAZZY trying to diagnose but alas the mystery was solved (1 year later).