[roscoFJ73]

Originally Posted by 2001Slayer

The the light will not come on if the vehicle is moved forward or backward. Any ideas what could be in the 4WD system that is affected by heat?

I would expect it to go into 4wd easier when warm. I suspect an electrical malfunction.
If it was mechanical the problem would be constant.
Im not too familiar with these but I would inspect the shift solenoid on the t/case.
Keep driving around from cold ,shifting in and out till it stops working.

If possible ,see if it can be shifted in/out by hand with the solenoid removed. That would definately isolate it between mechanical and electrical or test the voltage at the solenoid cold and warm