86 740 gle altenator grnd wire getting hot. New altenator. Any ideas.

 

Is the whole wire getting hot or just the place where it connects? You can also check the other engine grounds for tightness.

 

whole wire. Will check main grounds today.

 

gounds ok. what now.

 

I'm guessing you installed a new alternator because the other one crapped out and the result was a no-start? Have you checked the battery? Have you charged the battery with a battery charger? The ground wire handles nearly the same current as the alternator's output so...when the alternator is being used inappropriately (charging a dead battery) a mass quantity of electricity is being produced. The alternator is designed to keep the battery topped off and to run the engine...it is NOT designed to charge dead batteries. If the battery ground wire is melty hot, you might consider a heavier case ground wire. I use 12 gauge wire on my cars...it's the yellow one in the picture...Charging a stone dead battery with an alternator is a good way to kill a new alternator.

 

Battery is charged. Getting 13.5 to 14+ volts across battery when running. So it seems like all is working??

 

What do you get when the engine is off? Also, have you actually tested, or had tested, the battery with a load test? Many failing batteries will show 12.5 volts or more but have no or little, reserve capacity. Assuming all is good, and the temp issue bothers you, merely add a secondary case to chassis ground using a healthy wire.