94 1500 auto, over drive stopped working last week and button no longer illuminates. Checked solenoids with voltmeter and do not get any resistance between the center hot wire when matched to either the overdrive solenoid prong or the part throttle unlock prong. replaced the solenoid pack and get a 32.0 ohms resistance between prongs on the new part. Installed this part and still no overdrive or part throttle unlock. replaced the switch up in the dash and still no over drive...I'm at a loss of where to look next. Also, I disassembled the first OD switch and checked the bulb and the bulb does illuminate when connected directly to 12v power. However, it will not illuminate when connected to the truck nor does it engage the OD. Sure would appreciate any advice you all might give..Thank yah much!

 

Got it solved this evening... turned out that the plug had 3 bare wires that were touching up under the insulation. Pulled it all apart and rewrapped each wire separately and all seems to be functioning once again. Just thought I'd give y'all the solution in case you ever find yourself with the same situation I was facing.

 

Glad you fixed the problem!