Ok so i installed a 6A box on my 75 Toyota. Now it wants to keep running after looking at posts i found. To use a diode on the alternator charge light wire. But this did not fix me. I noticed it only did the run on after key off when she got to norm temp. On said Toyota i had previously installed a electric fan for a little extra power. I unhooked the fan while at norm temp for a couple seconds and it shut off everytime. with it hooked up and running vehicle kept running so i added a second diode to the power wire of the fan and works great now. Hope this helps others with this problem.