hi im new to the forum i just bought a 91 w150 with 318 that has 3 speed with overdrive. The other day I noticed od wasn't engaging checked solenoid plug and it wasn't plugged in, i plugged it in and the truck wouldn't start then plug started smoking and melted together wondering if anyone has had this problem

 

There is a short inside the trans that's why it was disconnected. You may now have damaged the pcm also. Need figure out the problem in the trans and go from there.

 

Any recommendations on what to test I have no transmission experience so any help is appreciated

 

Get a manual for the truck, It will explain a lot and have a wiring diagram. You need to drop the pan and valve body then inspect/investigate where the short is. This is still an hydraulically controlled trans for the most part so it's not to difficult.

 

Ok I have a Haynes manual I'll try and find thanks for the help I'm assuming I should get a new solenoid before I do this